Header And Logo
|
#include "postgres.h"#include <ctype.h>#include <math.h>#include "access/gin.h"#include "access/htup_details.h"#include "access/sysattr.h"#include "catalog/index.h"#include "catalog/pg_collation.h"#include "catalog/pg_opfamily.h"#include "catalog/pg_statistic.h"#include "catalog/pg_type.h"#include "executor/executor.h"#include "mb/pg_wchar.h"#include "nodes/makefuncs.h"#include "nodes/nodeFuncs.h"#include "optimizer/clauses.h"#include "optimizer/cost.h"#include "optimizer/pathnode.h"#include "optimizer/paths.h"#include "optimizer/plancat.h"#include "optimizer/predtest.h"#include "optimizer/restrictinfo.h"#include "optimizer/var.h"#include "parser/parse_clause.h"#include "parser/parse_coerce.h"#include "parser/parsetree.h"#include "utils/builtins.h"#include "utils/bytea.h"#include "utils/date.h"#include "utils/datum.h"#include "utils/fmgroids.h"#include "utils/lsyscache.h"#include "utils/nabstime.h"#include "utils/pg_locale.h"#include "utils/rel.h"#include "utils/selfuncs.h"#include "utils/spccache.h"#include "utils/syscache.h"#include "utils/timestamp.h"#include "utils/tqual.h"#include "utils/typcache.h"
Go to the source code of this file.
Data Structures | |
| struct | GroupVarInfo |
| struct | GenericCosts |
| struct | GinQualCounts |
Defines | |
| #define | FIXED_CHAR_SEL 0.20 |
| #define | CHAR_RANGE_SEL 0.25 |
| #define | ANY_CHAR_SEL 0.9 |
| #define | FULL_WILDCARD_SEL 5.0 |
| #define | PARTIAL_WILDCARD_SEL 2.0 |
Functions | |
| static double | var_eq_const (VariableStatData *vardata, Oid operator, Datum constval, bool constisnull, bool varonleft) |
| static double | var_eq_non_const (VariableStatData *vardata, Oid operator, Node *other, bool varonleft) |
| static double | ineq_histogram_selectivity (PlannerInfo *root, VariableStatData *vardata, FmgrInfo *opproc, bool isgt, Datum constval, Oid consttype) |
| static double | eqjoinsel_inner (Oid operator, VariableStatData *vardata1, VariableStatData *vardata2) |
| static double | eqjoinsel_semi (Oid operator, VariableStatData *vardata1, VariableStatData *vardata2, RelOptInfo *inner_rel) |
| static bool | convert_to_scalar (Datum value, Oid valuetypid, double *scaledvalue, Datum lobound, Datum hibound, Oid boundstypid, double *scaledlobound, double *scaledhibound) |
| static double | convert_numeric_to_scalar (Datum value, Oid typid) |
| static void | convert_string_to_scalar (char *value, double *scaledvalue, char *lobound, double *scaledlobound, char *hibound, double *scaledhibound) |
| static void | convert_bytea_to_scalar (Datum value, double *scaledvalue, Datum lobound, double *scaledlobound, Datum hibound, double *scaledhibound) |
| static double | convert_one_string_to_scalar (char *value, int rangelo, int rangehi) |
| static double | convert_one_bytea_to_scalar (unsigned char *value, int valuelen, int rangelo, int rangehi) |
| static char * | convert_string_datum (Datum value, Oid typid) |
| static double | convert_timevalue_to_scalar (Datum value, Oid typid) |
| static void | examine_simple_variable (PlannerInfo *root, Var *var, VariableStatData *vardata) |
| static bool | get_variable_range (PlannerInfo *root, VariableStatData *vardata, Oid sortop, Datum *min, Datum *max) |
| static bool | get_actual_variable_range (PlannerInfo *root, VariableStatData *vardata, Oid sortop, Datum *min, Datum *max) |
| static RelOptInfo * | find_join_input_rel (PlannerInfo *root, Relids relids) |
| static Selectivity | prefix_selectivity (PlannerInfo *root, VariableStatData *vardata, Oid vartype, Oid opfamily, Const *prefixcon) |
| static Selectivity | like_selectivity (const char *patt, int pattlen, bool case_insensitive) |
| static Selectivity | regex_selectivity (const char *patt, int pattlen, bool case_insensitive, int fixed_prefix_len) |
| static Datum | string_to_datum (const char *str, Oid datatype) |
| static Const * | string_to_const (const char *str, Oid datatype) |
| static Const * | string_to_bytea_const (const char *str, size_t str_len) |
| static List * | add_predicate_to_quals (IndexOptInfo *index, List *indexQuals) |
| Datum | eqsel (PG_FUNCTION_ARGS) |
| Datum | neqsel (PG_FUNCTION_ARGS) |
| static double | scalarineqsel (PlannerInfo *root, Oid operator, bool isgt, VariableStatData *vardata, Datum constval, Oid consttype) |
| double | mcv_selectivity (VariableStatData *vardata, FmgrInfo *opproc, Datum constval, bool varonleft, double *sumcommonp) |
| double | histogram_selectivity (VariableStatData *vardata, FmgrInfo *opproc, Datum constval, bool varonleft, int min_hist_size, int n_skip, int *hist_size) |
| Datum | scalarltsel (PG_FUNCTION_ARGS) |
| Datum | scalargtsel (PG_FUNCTION_ARGS) |
| static double | patternsel (PG_FUNCTION_ARGS, Pattern_Type ptype, bool negate) |
| Datum | regexeqsel (PG_FUNCTION_ARGS) |
| Datum | icregexeqsel (PG_FUNCTION_ARGS) |
| Datum | likesel (PG_FUNCTION_ARGS) |
| Datum | iclikesel (PG_FUNCTION_ARGS) |
| Datum | regexnesel (PG_FUNCTION_ARGS) |
| Datum | icregexnesel (PG_FUNCTION_ARGS) |
| Datum | nlikesel (PG_FUNCTION_ARGS) |
| Datum | icnlikesel (PG_FUNCTION_ARGS) |
| Selectivity | booltestsel (PlannerInfo *root, BoolTestType booltesttype, Node *arg, int varRelid, JoinType jointype, SpecialJoinInfo *sjinfo) |
| Selectivity | nulltestsel (PlannerInfo *root, NullTestType nulltesttype, Node *arg, int varRelid, JoinType jointype, SpecialJoinInfo *sjinfo) |
| static Node * | strip_array_coercion (Node *node) |
| Selectivity | scalararraysel (PlannerInfo *root, ScalarArrayOpExpr *clause, bool is_join_clause, int varRelid, JoinType jointype, SpecialJoinInfo *sjinfo) |
| int | estimate_array_length (Node *arrayexpr) |
| Selectivity | rowcomparesel (PlannerInfo *root, RowCompareExpr *clause, int varRelid, JoinType jointype, SpecialJoinInfo *sjinfo) |
| Datum | eqjoinsel (PG_FUNCTION_ARGS) |
| Datum | neqjoinsel (PG_FUNCTION_ARGS) |
| Datum | scalarltjoinsel (PG_FUNCTION_ARGS) |
| Datum | scalargtjoinsel (PG_FUNCTION_ARGS) |
| static double | patternjoinsel (PG_FUNCTION_ARGS, Pattern_Type ptype, bool negate) |
| Datum | regexeqjoinsel (PG_FUNCTION_ARGS) |
| Datum | icregexeqjoinsel (PG_FUNCTION_ARGS) |
| Datum | likejoinsel (PG_FUNCTION_ARGS) |
| Datum | iclikejoinsel (PG_FUNCTION_ARGS) |
| Datum | regexnejoinsel (PG_FUNCTION_ARGS) |
| Datum | icregexnejoinsel (PG_FUNCTION_ARGS) |
| Datum | nlikejoinsel (PG_FUNCTION_ARGS) |
| Datum | icnlikejoinsel (PG_FUNCTION_ARGS) |
| void | mergejoinscansel (PlannerInfo *root, Node *clause, Oid opfamily, int strategy, bool nulls_first, Selectivity *leftstart, Selectivity *leftend, Selectivity *rightstart, Selectivity *rightend) |
| static List * | add_unique_group_var (PlannerInfo *root, List *varinfos, Node *var, VariableStatData *vardata) |
| double | estimate_num_groups (PlannerInfo *root, List *groupExprs, double input_rows) |
| Selectivity | estimate_hash_bucketsize (PlannerInfo *root, Node *hashkey, double nbuckets) |
| bool | get_restriction_variable (PlannerInfo *root, List *args, int varRelid, VariableStatData *vardata, Node **other, bool *varonleft) |
| void | get_join_variables (PlannerInfo *root, List *args, SpecialJoinInfo *sjinfo, VariableStatData *vardata1, VariableStatData *vardata2, bool *join_is_reversed) |
| void | examine_variable (PlannerInfo *root, Node *node, int varRelid, VariableStatData *vardata) |
| double | get_variable_numdistinct (VariableStatData *vardata, bool *isdefault) |
| static int | pattern_char_isalpha (char c, bool is_multibyte, pg_locale_t locale, bool locale_is_c) |
| static Pattern_Prefix_Status | like_fixed_prefix (Const *patt_const, bool case_insensitive, Oid collation, Const **prefix_const, Selectivity *rest_selec) |
| static Pattern_Prefix_Status | regex_fixed_prefix (Const *patt_const, bool case_insensitive, Oid collation, Const **prefix_const, Selectivity *rest_selec) |
| Pattern_Prefix_Status | pattern_fixed_prefix (Const *patt, Pattern_Type ptype, Oid collation, Const **prefix, Selectivity *rest_selec) |
| static Selectivity | regex_selectivity_sub (const char *patt, int pattlen, bool case_insensitive) |
| static bool | byte_increment (unsigned char *ptr, int len) |
| Const * | make_greater_string (const Const *str_const, FmgrInfo *ltproc, Oid collation) |
| static void | genericcostestimate (PlannerInfo *root, IndexPath *path, double loop_count, GenericCosts *costs) |
| Datum | btcostestimate (PG_FUNCTION_ARGS) |
| Datum | hashcostestimate (PG_FUNCTION_ARGS) |
| Datum | gistcostestimate (PG_FUNCTION_ARGS) |
| Datum | spgcostestimate (PG_FUNCTION_ARGS) |
| static int | find_index_column (Node *op, IndexOptInfo *index) |
| static bool | gincost_pattern (IndexOptInfo *index, int indexcol, Oid clause_op, Datum query, GinQualCounts *counts) |
| static bool | gincost_opexpr (IndexOptInfo *index, OpExpr *clause, GinQualCounts *counts) |
| static bool | gincost_scalararrayopexpr (IndexOptInfo *index, ScalarArrayOpExpr *clause, double numIndexEntries, GinQualCounts *counts) |
| Datum | gincostestimate (PG_FUNCTION_ARGS) |
Variables | |
| get_relation_stats_hook_type | get_relation_stats_hook = NULL |
| get_index_stats_hook_type | get_index_stats_hook = NULL |
| #define ANY_CHAR_SEL 0.9 |
Definition at line 5474 of file selfuncs.c.
| #define CHAR_RANGE_SEL 0.25 |
Definition at line 5473 of file selfuncs.c.
Referenced by regex_selectivity_sub().
| #define FIXED_CHAR_SEL 0.20 |
Definition at line 5472 of file selfuncs.c.
Referenced by regex_selectivity().
| #define FULL_WILDCARD_SEL 5.0 |
Definition at line 5475 of file selfuncs.c.
| #define PARTIAL_WILDCARD_SEL 2.0 |
Definition at line 5476 of file selfuncs.c.
| static List * add_predicate_to_quals | ( | IndexOptInfo * | index, | |
| List * | indexQuals | |||
| ) | [static] |
Definition at line 6172 of file selfuncs.c.
References IndexOptInfo::indpred, lfirst, list_concat(), list_make1, NIL, and predicate_implied_by().
Referenced by btcostestimate(), and genericcostestimate().
{
List *predExtraQuals = NIL;
ListCell *lc;
if (index->indpred == NIL)
return indexQuals;
foreach(lc, index->indpred)
{
Node *predQual = (Node *) lfirst(lc);
List *oneQual = list_make1(predQual);
if (!predicate_implied_by(oneQual, indexQuals))
predExtraQuals = list_concat(predExtraQuals, oneQual);
}
/* list_concat avoids modifying the passed-in indexQuals list */
return list_concat(predExtraQuals, indexQuals);
}
| static List* add_unique_group_var | ( | PlannerInfo * | root, | |
| List * | varinfos, | |||
| Node * | var, | |||
| VariableStatData * | vardata | |||
| ) | [static] |
Definition at line 3090 of file selfuncs.c.
References equal(), exprs_known_equal(), get_variable_numdistinct(), lappend(), lfirst, list_delete_ptr(), list_head(), lnext, GroupVarInfo::ndistinct, palloc(), GroupVarInfo::rel, VariableStatData::rel, and GroupVarInfo::var.
Referenced by estimate_num_groups().
{
GroupVarInfo *varinfo;
double ndistinct;
bool isdefault;
ListCell *lc;
ndistinct = get_variable_numdistinct(vardata, &isdefault);
/* cannot use foreach here because of possible list_delete */
lc = list_head(varinfos);
while (lc)
{
varinfo = (GroupVarInfo *) lfirst(lc);
/* must advance lc before list_delete possibly pfree's it */
lc = lnext(lc);
/* Drop exact duplicates */
if (equal(var, varinfo->var))
return varinfos;
/*
* Drop known-equal vars, but only if they belong to different
* relations (see comments for estimate_num_groups)
*/
if (vardata->rel != varinfo->rel &&
exprs_known_equal(root, var, varinfo->var))
{
if (varinfo->ndistinct <= ndistinct)
{
/* Keep older item, forget new one */
return varinfos;
}
else
{
/* Delete the older item */
varinfos = list_delete_ptr(varinfos, varinfo);
}
}
}
varinfo = (GroupVarInfo *) palloc(sizeof(GroupVarInfo));
varinfo->var = var;
varinfo->rel = vardata->rel;
varinfo->ndistinct = ndistinct;
varinfos = lappend(varinfos, varinfo);
return varinfos;
}
| Selectivity booltestsel | ( | PlannerInfo * | root, | |
| BoolTestType | booltesttype, | |||
| Node * | arg, | |||
| int | varRelid, | |||
| JoinType | jointype, | |||
| SpecialJoinInfo * | sjinfo | |||
| ) |
Definition at line 1446 of file selfuncs.c.
References VariableStatData::atttype, VariableStatData::atttypmod, CLAMP_PROBABILITY, clause_selectivity(), DatumGetBool, elog, ERROR, examine_variable(), free_attstatsslot(), get_attstatsslot(), GETSTRUCT, HeapTupleIsValid, InvalidOid, IS_FALSE, IS_NOT_FALSE, IS_NOT_TRUE, IS_NOT_UNKNOWN, IS_TRUE, IS_UNKNOWN, NULL, ReleaseVariableStats, STATISTIC_KIND_MCV, VariableStatData::statsTuple, and values.
Referenced by clause_selectivity().
{
VariableStatData vardata;
double selec;
examine_variable(root, arg, varRelid, &vardata);
if (HeapTupleIsValid(vardata.statsTuple))
{
Form_pg_statistic stats;
double freq_null;
Datum *values;
int nvalues;
float4 *numbers;
int nnumbers;
stats = (Form_pg_statistic) GETSTRUCT(vardata.statsTuple);
freq_null = stats->stanullfrac;
if (get_attstatsslot(vardata.statsTuple,
vardata.atttype, vardata.atttypmod,
STATISTIC_KIND_MCV, InvalidOid,
NULL,
&values, &nvalues,
&numbers, &nnumbers)
&& nnumbers > 0)
{
double freq_true;
double freq_false;
/*
* Get first MCV frequency and derive frequency for true.
*/
if (DatumGetBool(values[0]))
freq_true = numbers[0];
else
freq_true = 1.0 - numbers[0] - freq_null;
/*
* Next derive frequency for false. Then use these as appropriate
* to derive frequency for each case.
*/
freq_false = 1.0 - freq_true - freq_null;
switch (booltesttype)
{
case IS_UNKNOWN:
/* select only NULL values */
selec = freq_null;
break;
case IS_NOT_UNKNOWN:
/* select non-NULL values */
selec = 1.0 - freq_null;
break;
case IS_TRUE:
/* select only TRUE values */
selec = freq_true;
break;
case IS_NOT_TRUE:
/* select non-TRUE values */
selec = 1.0 - freq_true;
break;
case IS_FALSE:
/* select only FALSE values */
selec = freq_false;
break;
case IS_NOT_FALSE:
/* select non-FALSE values */
selec = 1.0 - freq_false;
break;
default:
elog(ERROR, "unrecognized booltesttype: %d",
(int) booltesttype);
selec = 0.0; /* Keep compiler quiet */
break;
}
free_attstatsslot(vardata.atttype, values, nvalues,
numbers, nnumbers);
}
else
{
/*
* No most-common-value info available. Still have null fraction
* information, so use it for IS [NOT] UNKNOWN. Otherwise adjust
* for null fraction and assume an even split for boolean tests.
*/
switch (booltesttype)
{
case IS_UNKNOWN:
/*
* Use freq_null directly.
*/
selec = freq_null;
break;
case IS_NOT_UNKNOWN:
/*
* Select not unknown (not null) values. Calculate from
* freq_null.
*/
selec = 1.0 - freq_null;
break;
case IS_TRUE:
case IS_NOT_TRUE:
case IS_FALSE:
case IS_NOT_FALSE:
selec = (1.0 - freq_null) / 2.0;
break;
default:
elog(ERROR, "unrecognized booltesttype: %d",
(int) booltesttype);
selec = 0.0; /* Keep compiler quiet */
break;
}
}
}
else
{
/*
* If we can't get variable statistics for the argument, perhaps
* clause_selectivity can do something with it. We ignore the
* possibility of a NULL value when using clause_selectivity, and just
* assume the value is either TRUE or FALSE.
*/
switch (booltesttype)
{
case IS_UNKNOWN:
selec = DEFAULT_UNK_SEL;
break;
case IS_NOT_UNKNOWN:
selec = DEFAULT_NOT_UNK_SEL;
break;
case IS_TRUE:
case IS_NOT_FALSE:
selec = (double) clause_selectivity(root, arg,
varRelid,
jointype, sjinfo);
break;
case IS_FALSE:
case IS_NOT_TRUE:
selec = 1.0 - (double) clause_selectivity(root, arg,
varRelid,
jointype, sjinfo);
break;
default:
elog(ERROR, "unrecognized booltesttype: %d",
(int) booltesttype);
selec = 0.0; /* Keep compiler quiet */
break;
}
}
ReleaseVariableStats(vardata);
/* result should be in range, but make sure... */
CLAMP_PROBABILITY(selec);
return (Selectivity) selec;
}
| Datum btcostestimate | ( | PG_FUNCTION_ARGS | ) |
Definition at line 6194 of file selfuncs.c.
References add_predicate_to_quals(), NullTest::arg, ScalarArrayOpExpr::args, Assert, BoolGetDatum, BTEqualStrategyNumber, BTLessStrategyNumber, RestrictInfo::clause, clauselist_selectivity(), cpu_operator_cost, elog, ERROR, estimate_array_length(), forboth, free_attstatsslot(), VariableStatData::freefunc, genericcostestimate(), get_attstatsslot(), get_commutator(), get_index_stats_hook, get_leftop(), get_op_opfamily_strategy(), get_opfamily_member(), get_relation_stats_hook, get_rightop(), HeapTupleIsValid, GenericCosts::indexCorrelation, IndexPath::indexinfo, IndexOptInfo::indexkeys, IndexOptInfo::indexoid, IndexPath::indexqualcols, IndexPath::indexquals, GenericCosts::indexSelectivity, GenericCosts::indexStartupCost, GenericCosts::indexTotalCost, RangeTblEntry::inh, Int16GetDatum, InvalidOid, IS_NULL, IsA, JOIN_INNER, lappend(), RowCompareExpr::largs, lfirst, lfirst_int, linitial, linitial_oid, lsecond, match_index_to_operand(), MemSet, IndexOptInfo::ncolumns, nodeTag, NULL, NullTest::nulltesttype, GenericCosts::num_sa_scans, GenericCosts::numIndexTuples, ObjectIdGetDatum, OidIsValid, IndexOptInfo::opcintype, IndexOptInfo::opfamily, ScalarArrayOpExpr::opno, RowCompareExpr::opnos, PG_GETARG_FLOAT8, PG_GETARG_POINTER, PG_RETURN_VOID, planner_rt_fetch, RowCompareExpr::rargs, IndexOptInfo::rel, ReleaseVariableStats, RangeTblEntry::relid, RelOptInfo::relid, IndexOptInfo::reverse_sort, rint(), RTE_RELATION, RangeTblEntry::rtekind, SearchSysCache3, STATISTIC_KIND_CORRELATION, STATRELATTINH, VariableStatData::statsTuple, IndexOptInfo::tree_height, IndexOptInfo::tuples, RelOptInfo::tuples, and IndexOptInfo::unique.
{
PlannerInfo *root = (PlannerInfo *) PG_GETARG_POINTER(0);
IndexPath *path = (IndexPath *) PG_GETARG_POINTER(1);
double loop_count = PG_GETARG_FLOAT8(2);
Cost *indexStartupCost = (Cost *) PG_GETARG_POINTER(3);
Cost *indexTotalCost = (Cost *) PG_GETARG_POINTER(4);
Selectivity *indexSelectivity = (Selectivity *) PG_GETARG_POINTER(5);
double *indexCorrelation = (double *) PG_GETARG_POINTER(6);
IndexOptInfo *index = path->indexinfo;
GenericCosts costs;
Oid relid;
AttrNumber colnum;
VariableStatData vardata;
double numIndexTuples;
Cost descentCost;
List *indexBoundQuals;
int indexcol;
bool eqQualHere;
bool found_saop;
bool found_is_null_op;
double num_sa_scans;
ListCell *lcc,
*lci;
/*
* For a btree scan, only leading '=' quals plus inequality quals for the
* immediately next attribute contribute to index selectivity (these are
* the "boundary quals" that determine the starting and stopping points of
* the index scan). Additional quals can suppress visits to the heap, so
* it's OK to count them in indexSelectivity, but they should not count
* for estimating numIndexTuples. So we must examine the given indexquals
* to find out which ones count as boundary quals. We rely on the
* knowledge that they are given in index column order.
*
* For a RowCompareExpr, we consider only the first column, just as
* rowcomparesel() does.
*
* If there's a ScalarArrayOpExpr in the quals, we'll actually perform N
* index scans not one, but the ScalarArrayOpExpr's operator can be
* considered to act the same as it normally does.
*/
indexBoundQuals = NIL;
indexcol = 0;
eqQualHere = false;
found_saop = false;
found_is_null_op = false;
num_sa_scans = 1;
forboth(lcc, path->indexquals, lci, path->indexqualcols)
{
RestrictInfo *rinfo = (RestrictInfo *) lfirst(lcc);
Expr *clause;
Node *leftop,
*rightop PG_USED_FOR_ASSERTS_ONLY;
Oid clause_op;
int op_strategy;
bool is_null_op = false;
if (indexcol != lfirst_int(lci))
{
/* Beginning of a new column's quals */
if (!eqQualHere)
break; /* done if no '=' qual for indexcol */
eqQualHere = false;
indexcol++;
if (indexcol != lfirst_int(lci))
break; /* no quals at all for indexcol */
}
Assert(IsA(rinfo, RestrictInfo));
clause = rinfo->clause;
if (IsA(clause, OpExpr))
{
leftop = get_leftop(clause);
rightop = get_rightop(clause);
clause_op = ((OpExpr *) clause)->opno;
}
else if (IsA(clause, RowCompareExpr))
{
RowCompareExpr *rc = (RowCompareExpr *) clause;
leftop = (Node *) linitial(rc->largs);
rightop = (Node *) linitial(rc->rargs);
clause_op = linitial_oid(rc->opnos);
}
else if (IsA(clause, ScalarArrayOpExpr))
{
ScalarArrayOpExpr *saop = (ScalarArrayOpExpr *) clause;
leftop = (Node *) linitial(saop->args);
rightop = (Node *) lsecond(saop->args);
clause_op = saop->opno;
found_saop = true;
}
else if (IsA(clause, NullTest))
{
NullTest *nt = (NullTest *) clause;
leftop = (Node *) nt->arg;
rightop = NULL;
clause_op = InvalidOid;
if (nt->nulltesttype == IS_NULL)
{
found_is_null_op = true;
is_null_op = true;
}
}
else
{
elog(ERROR, "unsupported indexqual type: %d",
(int) nodeTag(clause));
continue; /* keep compiler quiet */
}
if (match_index_to_operand(leftop, indexcol, index))
{
/* clause_op is correct */
}
else
{
Assert(match_index_to_operand(rightop, indexcol, index));
/* Must flip operator to get the opfamily member */
clause_op = get_commutator(clause_op);
}
/* check for equality operator */
if (OidIsValid(clause_op))
{
op_strategy = get_op_opfamily_strategy(clause_op,
index->opfamily[indexcol]);
Assert(op_strategy != 0); /* not a member of opfamily?? */
if (op_strategy == BTEqualStrategyNumber)
eqQualHere = true;
}
else if (is_null_op)
{
/* IS NULL is like = for purposes of selectivity determination */
eqQualHere = true;
}
/* count up number of SA scans induced by indexBoundQuals only */
if (IsA(clause, ScalarArrayOpExpr))
{
ScalarArrayOpExpr *saop = (ScalarArrayOpExpr *) clause;
int alength = estimate_array_length(lsecond(saop->args));
if (alength > 1)
num_sa_scans *= alength;
}
indexBoundQuals = lappend(indexBoundQuals, rinfo);
}
/*
* If index is unique and we found an '=' clause for each column, we can
* just assume numIndexTuples = 1 and skip the expensive
* clauselist_selectivity calculations. However, a ScalarArrayOp or
* NullTest invalidates that theory, even though it sets eqQualHere.
*/
if (index->unique &&
indexcol == index->ncolumns - 1 &&
eqQualHere &&
!found_saop &&
!found_is_null_op)
numIndexTuples = 1.0;
else
{
List *selectivityQuals;
Selectivity btreeSelectivity;
/*
* If the index is partial, AND the index predicate with the
* index-bound quals to produce a more accurate idea of the number of
* rows covered by the bound conditions.
*/
selectivityQuals = add_predicate_to_quals(index, indexBoundQuals);
btreeSelectivity = clauselist_selectivity(root, selectivityQuals,
index->rel->relid,
JOIN_INNER,
NULL);
numIndexTuples = btreeSelectivity * index->rel->tuples;
/*
* As in genericcostestimate(), we have to adjust for any
* ScalarArrayOpExpr quals included in indexBoundQuals, and then round
* to integer.
*/
numIndexTuples = rint(numIndexTuples / num_sa_scans);
}
/*
* Now do generic index cost estimation.
*/
MemSet(&costs, 0, sizeof(costs));
costs.numIndexTuples = numIndexTuples;
genericcostestimate(root, path, loop_count, &costs);
/*
* Add a CPU-cost component to represent the costs of initial btree
* descent. We don't charge any I/O cost for touching upper btree levels,
* since they tend to stay in cache, but we still have to do about log2(N)
* comparisons to descend a btree of N leaf tuples. We charge one
* cpu_operator_cost per comparison.
*
* If there are ScalarArrayOpExprs, charge this once per SA scan. The
* ones after the first one are not startup cost so far as the overall
* plan is concerned, so add them only to "total" cost.
*/
if (index->tuples > 1) /* avoid computing log(0) */
{
descentCost = ceil(log(index->tuples) / log(2.0)) * cpu_operator_cost;
costs.indexStartupCost += descentCost;
costs.indexTotalCost += costs.num_sa_scans * descentCost;
}
/*
* Even though we're not charging I/O cost for touching upper btree pages,
* it's still reasonable to charge some CPU cost per page descended
* through. Moreover, if we had no such charge at all, bloated indexes
* would appear to have the same search cost as unbloated ones, at least
* in cases where only a single leaf page is expected to be visited. This
* cost is somewhat arbitrarily set at 50x cpu_operator_cost per page
* touched. The number of such pages is btree tree height plus one (ie,
* we charge for the leaf page too). As above, charge once per SA scan.
*/
descentCost = (index->tree_height + 1) * 50.0 * cpu_operator_cost;
costs.indexStartupCost += descentCost;
costs.indexTotalCost += costs.num_sa_scans * descentCost;
/*
* If we can get an estimate of the first column's ordering correlation C
* from pg_statistic, estimate the index correlation as C for a
* single-column index, or C * 0.75 for multiple columns. (The idea here
* is that multiple columns dilute the importance of the first column's
* ordering, but don't negate it entirely. Before 8.0 we divided the
* correlation by the number of columns, but that seems too strong.)
*/
MemSet(&vardata, 0, sizeof(vardata));
if (index->indexkeys[0] != 0)
{
/* Simple variable --- look to stats for the underlying table */
RangeTblEntry *rte = planner_rt_fetch(index->rel->relid, root);
Assert(rte->rtekind == RTE_RELATION);
relid = rte->relid;
Assert(relid != InvalidOid);
colnum = index->indexkeys[0];
if (get_relation_stats_hook &&
(*get_relation_stats_hook) (root, rte, colnum, &vardata))
{
/*
* The hook took control of acquiring a stats tuple. If it did
* supply a tuple, it'd better have supplied a freefunc.
*/
if (HeapTupleIsValid(vardata.statsTuple) &&
!vardata.freefunc)
elog(ERROR, "no function provided to release variable stats with");
}
else
{
vardata.statsTuple = SearchSysCache3(STATRELATTINH,
ObjectIdGetDatum(relid),
Int16GetDatum(colnum),
BoolGetDatum(rte->inh));
vardata.freefunc = ReleaseSysCache;
}
}
else
{
/* Expression --- maybe there are stats for the index itself */
relid = index->indexoid;
colnum = 1;
if (get_index_stats_hook &&
(*get_index_stats_hook) (root, relid, colnum, &vardata))
{
/*
* The hook took control of acquiring a stats tuple. If it did
* supply a tuple, it'd better have supplied a freefunc.
*/
if (HeapTupleIsValid(vardata.statsTuple) &&
!vardata.freefunc)
elog(ERROR, "no function provided to release variable stats with");
}
else
{
vardata.statsTuple = SearchSysCache3(STATRELATTINH,
ObjectIdGetDatum(relid),
Int16GetDatum(colnum),
BoolGetDatum(false));
vardata.freefunc = ReleaseSysCache;
}
}
if (HeapTupleIsValid(vardata.statsTuple))
{
Oid sortop;
float4 *numbers;
int nnumbers;
sortop = get_opfamily_member(index->opfamily[0],
index->opcintype[0],
index->opcintype[0],
BTLessStrategyNumber);
if (OidIsValid(sortop) &&
get_attstatsslot(vardata.statsTuple, InvalidOid, 0,
STATISTIC_KIND_CORRELATION,
sortop,
NULL,
NULL, NULL,
&numbers, &nnumbers))
{
double varCorrelation;
Assert(nnumbers == 1);
varCorrelation = numbers[0];
if (index->reverse_sort[0])
varCorrelation = -varCorrelation;
if (index->ncolumns > 1)
costs.indexCorrelation = varCorrelation * 0.75;
else
costs.indexCorrelation = varCorrelation;
free_attstatsslot(InvalidOid, NULL, 0, numbers, nnumbers);
}
}
ReleaseVariableStats(vardata);
*indexStartupCost = costs.indexStartupCost;
*indexTotalCost = costs.indexTotalCost;
*indexSelectivity = costs.indexSelectivity;
*indexCorrelation = costs.indexCorrelation;
PG_RETURN_VOID();
}
| static bool byte_increment | ( | unsigned char * | ptr, | |
| int | len | |||
| ) | [static] |
Definition at line 5643 of file selfuncs.c.
{
if (*ptr >= 255)
return false;
(*ptr)++;
return true;
}
| static void convert_bytea_to_scalar | ( | Datum | value, | |
| double * | scaledvalue, | |||
| Datum | lobound, | |||
| double * | scaledlobound, | |||
| Datum | hibound, | |||
| double * | scaledhibound | |||
| ) | [static] |
Definition at line 3974 of file selfuncs.c.
References convert_one_bytea_to_scalar(), DatumGetPointer, i, Min, VARDATA, and VARSIZE.
Referenced by convert_to_scalar().
{
int rangelo,
rangehi,
valuelen = VARSIZE(DatumGetPointer(value)) - VARHDRSZ,
loboundlen = VARSIZE(DatumGetPointer(lobound)) - VARHDRSZ,
hiboundlen = VARSIZE(DatumGetPointer(hibound)) - VARHDRSZ,
i,
minlen;
unsigned char *valstr = (unsigned char *) VARDATA(DatumGetPointer(value)),
*lostr = (unsigned char *) VARDATA(DatumGetPointer(lobound)),
*histr = (unsigned char *) VARDATA(DatumGetPointer(hibound));
/*
* Assume bytea data is uniformly distributed across all byte values.
*/
rangelo = 0;
rangehi = 255;
/*
* Now strip any common prefix of the three strings.
*/
minlen = Min(Min(valuelen, loboundlen), hiboundlen);
for (i = 0; i < minlen; i++)
{
if (*lostr != *histr || *lostr != *valstr)
break;
lostr++, histr++, valstr++;
loboundlen--, hiboundlen--, valuelen--;
}
/*
* Now we can do the conversions.
*/
*scaledvalue = convert_one_bytea_to_scalar(valstr, valuelen, rangelo, rangehi);
*scaledlobound = convert_one_bytea_to_scalar(lostr, loboundlen, rangelo, rangehi);
*scaledhibound = convert_one_bytea_to_scalar(histr, hiboundlen, rangelo, rangehi);
}
Definition at line 3687 of file selfuncs.c.
References BOOLOID, DatumGetBool, DatumGetFloat4, DatumGetFloat8, DatumGetInt16, DatumGetInt32, DatumGetInt64, DatumGetObjectId, DirectFunctionCall1, elog, ERROR, FLOAT4OID, FLOAT8OID, INT2OID, INT4OID, INT8OID, numeric_float8_no_overflow(), NUMERICOID, OIDOID, REGCLASSOID, REGCONFIGOID, REGDICTIONARYOID, REGOPERATOROID, REGOPEROID, REGPROCEDUREOID, REGPROCOID, and REGTYPEOID.
Referenced by convert_to_scalar().
{
switch (typid)
{
case BOOLOID:
return (double) DatumGetBool(value);
case INT2OID:
return (double) DatumGetInt16(value);
case INT4OID:
return (double) DatumGetInt32(value);
case INT8OID:
return (double) DatumGetInt64(value);
case FLOAT4OID:
return (double) DatumGetFloat4(value);
case FLOAT8OID:
return (double) DatumGetFloat8(value);
case NUMERICOID:
/* Note: out-of-range values will be clamped to +-HUGE_VAL */
return (double)
DatumGetFloat8(DirectFunctionCall1(numeric_float8_no_overflow,
value));
case OIDOID:
case REGPROCOID:
case REGPROCEDUREOID:
case REGOPEROID:
case REGOPERATOROID:
case REGCLASSOID:
case REGTYPEOID:
case REGCONFIGOID:
case REGDICTIONARYOID:
/* we can treat OIDs as integers... */
return (double) DatumGetObjectId(value);
}
/*
* Can't get here unless someone tries to use scalarltsel/scalargtsel on
* an operator with one numeric and one non-numeric operand.
*/
elog(ERROR, "unsupported type: %u", typid);
return 0;
}
| static double convert_one_bytea_to_scalar | ( | unsigned char * | value, | |
| int | valuelen, | |||
| int | rangelo, | |||
| int | rangehi | |||
| ) | [static] |
Definition at line 4019 of file selfuncs.c.
Referenced by convert_bytea_to_scalar().
{
double num,
denom,
base;
if (valuelen <= 0)
return 0.0; /* empty string has scalar value 0 */
/*
* Since base is 256, need not consider more than about 10 chars (even
* this many seems like overkill)
*/
if (valuelen > 10)
valuelen = 10;
/* Convert initial characters to fraction */
base = rangehi - rangelo + 1;
num = 0.0;
denom = base;
while (valuelen-- > 0)
{
int ch = *value++;
if (ch < rangelo)
ch = rangelo - 1;
else if (ch > rangehi)
ch = rangehi + 1;
num += ((double) (ch - rangelo)) / denom;
denom *= base;
}
return num;
}
| static double convert_one_string_to_scalar | ( | char * | value, | |
| int | rangelo, | |||
| int | rangehi | |||
| ) | [static] |
Definition at line 3830 of file selfuncs.c.
Referenced by convert_string_to_scalar().
{
int slen = strlen(value);
double num,
denom,
base;
if (slen <= 0)
return 0.0; /* empty string has scalar value 0 */
/*
* Since base is at least 10, need not consider more than about 20 chars
*/
if (slen > 20)
slen = 20;
/* Convert initial characters to fraction */
base = rangehi - rangelo + 1;
num = 0.0;
denom = base;
while (slen-- > 0)
{
int ch = (unsigned char) *value++;
if (ch < rangelo)
ch = rangelo - 1;
else if (ch > rangehi)
ch = rangehi + 1;
num += ((double) (ch - rangelo)) / denom;
denom *= base;
}
return num;
}
Definition at line 3872 of file selfuncs.c.
References Assert, BPCHAROID, CHAROID, DatumGetChar, DatumGetPointer, DEFAULT_COLLATION_OID, elog, ERROR, lc_collate_is_c(), NAMEOID, NameStr, NULL, palloc(), pfree(), pstrdup(), TextDatumGetCString, TEXTOID, val, and VARCHAROID.
Referenced by convert_to_scalar().
{
char *val;
switch (typid)
{
case CHAROID:
val = (char *) palloc(2);
val[0] = DatumGetChar(value);
val[1] = '\0';
break;
case BPCHAROID:
case VARCHAROID:
case TEXTOID:
val = TextDatumGetCString(value);
break;
case NAMEOID:
{
NameData *nm = (NameData *) DatumGetPointer(value);
val = pstrdup(NameStr(*nm));
break;
}
default:
/*
* Can't get here unless someone tries to use scalarltsel on an
* operator with one string and one non-string operand.
*/
elog(ERROR, "unsupported type: %u", typid);
return NULL;
}
if (!lc_collate_is_c(DEFAULT_COLLATION_OID))
{
char *xfrmstr;
size_t xfrmlen;
size_t xfrmlen2 PG_USED_FOR_ASSERTS_ONLY;
/*
* Note: originally we guessed at a suitable output buffer size, and
* only needed to call strxfrm twice if our guess was too small.
* However, it seems that some versions of Solaris have buggy strxfrm
* that can write past the specified buffer length in that scenario.
* So, do it the dumb way for portability.
*
* Yet other systems (e.g., glibc) sometimes return a smaller value
* from the second call than the first; thus the Assert must be <= not
* == as you'd expect. Can't any of these people program their way
* out of a paper bag?
*
* XXX: strxfrm doesn't support UTF-8 encoding on Win32, it can return
* bogus data or set an error. This is not really a problem unless it
* crashes since it will only give an estimation error and nothing
* fatal.
*/
#if _MSC_VER == 1400 /* VS.Net 2005 */
/*
*
* http://connect.microsoft.com/VisualStudio/feedback/ViewFeedback.aspx?
* FeedbackID=99694 */
{
char x[1];
xfrmlen = strxfrm(x, val, 0);
}
#else
xfrmlen = strxfrm(NULL, val, 0);
#endif
#ifdef WIN32
/*
* On Windows, strxfrm returns INT_MAX when an error occurs. Instead
* of trying to allocate this much memory (and fail), just return the
* original string unmodified as if we were in the C locale.
*/
if (xfrmlen == INT_MAX)
return val;
#endif
xfrmstr = (char *) palloc(xfrmlen + 1);
xfrmlen2 = strxfrm(xfrmstr, val, xfrmlen + 1);
Assert(xfrmlen2 <= xfrmlen);
pfree(val);
val = xfrmstr;
}
return val;
}
| static void convert_string_to_scalar | ( | char * | value, | |
| double * | scaledvalue, | |||
| char * | lobound, | |||
| double * | scaledlobound, | |||
| char * | hibound, | |||
| double * | scaledhibound | |||
| ) | [static] |
Definition at line 3750 of file selfuncs.c.
References convert_one_string_to_scalar().
Referenced by convert_to_scalar().
{
int rangelo,
rangehi;
char *sptr;
rangelo = rangehi = (unsigned char) hibound[0];
for (sptr = lobound; *sptr; sptr++)
{
if (rangelo > (unsigned char) *sptr)
rangelo = (unsigned char) *sptr;
if (rangehi < (unsigned char) *sptr)
rangehi = (unsigned char) *sptr;
}
for (sptr = hibound; *sptr; sptr++)
{
if (rangelo > (unsigned char) *sptr)
rangelo = (unsigned char) *sptr;
if (rangehi < (unsigned char) *sptr)
rangehi = (unsigned char) *sptr;
}
/* If range includes any upper-case ASCII chars, make it include all */
if (rangelo <= 'Z' && rangehi >= 'A')
{
if (rangelo > 'A')
rangelo = 'A';
if (rangehi < 'Z')
rangehi = 'Z';
}
/* Ditto lower-case */
if (rangelo <= 'z' && rangehi >= 'a')
{
if (rangelo > 'a')
rangelo = 'a';
if (rangehi < 'z')
rangehi = 'z';
}
/* Ditto digits */
if (rangelo <= '9' && rangehi >= '0')
{
if (rangelo > '0')
rangelo = '0';
if (rangehi < '9')
rangehi = '9';
}
/*
* If range includes less than 10 chars, assume we have not got enough
* data, and make it include regular ASCII set.
*/
if (rangehi - rangelo < 9)
{
rangelo = ' ';
rangehi = 127;
}
/*
* Now strip any common prefix of the three strings.
*/
while (*lobound)
{
if (*lobound != *hibound || *lobound != *value)
break;
lobound++, hibound++, value++;
}
/*
* Now we can do the conversions.
*/
*scaledvalue = convert_one_string_to_scalar(value, rangelo, rangehi);
*scaledlobound = convert_one_string_to_scalar(lobound, rangelo, rangehi);
*scaledhibound = convert_one_string_to_scalar(hibound, rangelo, rangehi);
}
Definition at line 4059 of file selfuncs.c.
References abstime_timestamp(), ABSTIMEOID, TimeIntervalData::data, date2timestamp_no_overflow(), DATEOID, DatumGetDateADT, DatumGetIntervalP, DatumGetRelativeTime, DatumGetTimeADT, DatumGetTimeInterval, DatumGetTimestamp, DatumGetTimestampTz, DatumGetTimeTzADTP, Interval::day, DAYS_PER_YEAR, DirectFunctionCall1, elog, ERROR, INTERVALOID, Interval::month, MONTHS_PER_YEAR, RELTIMEOID, SECS_PER_DAY, TimeIntervalData::status, TimeTzADT::time, Interval::time, TIMEOID, TIMESTAMPOID, TIMESTAMPTZOID, TIMETZOID, TINTERVALOID, USECS_PER_DAY, and TimeTzADT::zone.
Referenced by convert_to_scalar().
{
switch (typid)
{
case TIMESTAMPOID:
return DatumGetTimestamp(value);
case TIMESTAMPTZOID:
return DatumGetTimestampTz(value);
case ABSTIMEOID:
return DatumGetTimestamp(DirectFunctionCall1(abstime_timestamp,
value));
case DATEOID:
return date2timestamp_no_overflow(DatumGetDateADT(value));
case INTERVALOID:
{
Interval *interval = DatumGetIntervalP(value);
/*
* Convert the month part of Interval to days using assumed
* average month length of 365.25/12.0 days. Not too
* accurate, but plenty good enough for our purposes.
*/
#ifdef HAVE_INT64_TIMESTAMP
return interval->time + interval->day * (double) USECS_PER_DAY +
interval->month * ((DAYS_PER_YEAR / (double) MONTHS_PER_YEAR) * USECS_PER_DAY);
#else
return interval->time + interval->day * SECS_PER_DAY +
interval->month * ((DAYS_PER_YEAR / (double) MONTHS_PER_YEAR) * (double) SECS_PER_DAY);
#endif
}
case RELTIMEOID:
#ifdef HAVE_INT64_TIMESTAMP
return (DatumGetRelativeTime(value) * 1000000.0);
#else
return DatumGetRelativeTime(value);
#endif
case TINTERVALOID:
{
TimeInterval tinterval = DatumGetTimeInterval(value);
#ifdef HAVE_INT64_TIMESTAMP
if (tinterval->status != 0)
return ((tinterval->data[1] - tinterval->data[0]) * 1000000.0);
#else
if (tinterval->status != 0)
return tinterval->data[1] - tinterval->data[0];
#endif
return 0; /* for lack of a better idea */
}
case TIMEOID:
return DatumGetTimeADT(value);
case TIMETZOID:
{
TimeTzADT *timetz = DatumGetTimeTzADTP(value);
/* use GMT-equivalent time */
#ifdef HAVE_INT64_TIMESTAMP
return (double) (timetz->time + (timetz->zone * 1000000.0));
#else
return (double) (timetz->time + timetz->zone);
#endif
}
}
/*
* Can't get here unless someone tries to use scalarltsel/scalargtsel on
* an operator with one timevalue and one non-timevalue operand.
*/
elog(ERROR, "unsupported type: %u", typid);
return 0;
}
| static bool convert_to_scalar | ( | Datum | value, | |
| Oid | valuetypid, | |||
| double * | scaledvalue, | |||
| Datum | lobound, | |||
| Datum | hibound, | |||
| Oid | boundstypid, | |||
| double * | scaledlobound, | |||
| double * | scaledhibound | |||
| ) | [static] |
Definition at line 3572 of file selfuncs.c.
References ABSTIMEOID, BOOLOID, BPCHAROID, BYTEAOID, CHAROID, CIDROID, convert_bytea_to_scalar(), convert_network_to_scalar(), convert_numeric_to_scalar(), convert_string_datum(), convert_string_to_scalar(), convert_timevalue_to_scalar(), DATEOID, FLOAT4OID, FLOAT8OID, INETOID, INT2OID, INT4OID, INT8OID, INTERVALOID, MACADDROID, NAMEOID, NUMERICOID, OIDOID, pfree(), REGCLASSOID, REGCONFIGOID, REGDICTIONARYOID, REGOPERATOROID, REGOPEROID, REGPROCEDUREOID, REGPROCOID, REGTYPEOID, RELTIMEOID, TEXTOID, TIMEOID, TIMESTAMPOID, TIMESTAMPTZOID, TIMETZOID, TINTERVALOID, and VARCHAROID.
Referenced by ineq_histogram_selectivity().
{
/*
* Both the valuetypid and the boundstypid should exactly match the
* declared input type(s) of the operator we are invoked for, so we just
* error out if either is not recognized.
*
* XXX The histogram we are interpolating between points of could belong
* to a column that's only binary-compatible with the declared type. In
* essence we are assuming that the semantics of binary-compatible types
* are enough alike that we can use a histogram generated with one type's
* operators to estimate selectivity for the other's. This is outright
* wrong in some cases --- in particular signed versus unsigned
* interpretation could trip us up. But it's useful enough in the
* majority of cases that we do it anyway. Should think about more
* rigorous ways to do it.
*/
switch (valuetypid)
{
/*
* Built-in numeric types
*/
case BOOLOID:
case INT2OID:
case INT4OID:
case INT8OID:
case FLOAT4OID:
case FLOAT8OID:
case NUMERICOID:
case OIDOID:
case REGPROCOID:
case REGPROCEDUREOID:
case REGOPEROID:
case REGOPERATOROID:
case REGCLASSOID:
case REGTYPEOID:
case REGCONFIGOID:
case REGDICTIONARYOID:
*scaledvalue = convert_numeric_to_scalar(value, valuetypid);
*scaledlobound = convert_numeric_to_scalar(lobound, boundstypid);
*scaledhibound = convert_numeric_to_scalar(hibound, boundstypid);
return true;
/*
* Built-in string types
*/
case CHAROID:
case BPCHAROID:
case VARCHAROID:
case TEXTOID:
case NAMEOID:
{
char *valstr = convert_string_datum(value, valuetypid);
char *lostr = convert_string_datum(lobound, boundstypid);
char *histr = convert_string_datum(hibound, boundstypid);
convert_string_to_scalar(valstr, scaledvalue,
lostr, scaledlobound,
histr, scaledhibound);
pfree(valstr);
pfree(lostr);
pfree(histr);
return true;
}
/*
* Built-in bytea type
*/
case BYTEAOID:
{
convert_bytea_to_scalar(value, scaledvalue,
lobound, scaledlobound,
hibound, scaledhibound);
return true;
}
/*
* Built-in time types
*/
case TIMESTAMPOID:
case TIMESTAMPTZOID:
case ABSTIMEOID:
case DATEOID:
case INTERVALOID:
case RELTIMEOID:
case TINTERVALOID:
case TIMEOID:
case TIMETZOID:
*scaledvalue = convert_timevalue_to_scalar(value, valuetypid);
*scaledlobound = convert_timevalue_to_scalar(lobound, boundstypid);
*scaledhibound = convert_timevalue_to_scalar(hibound, boundstypid);
return true;
/*
* Built-in network types
*/
case INETOID:
case CIDROID:
case MACADDROID:
*scaledvalue = convert_network_to_scalar(value, valuetypid);
*scaledlobound = convert_network_to_scalar(lobound, boundstypid);
*scaledhibound = convert_network_to_scalar(hibound, boundstypid);
return true;
}
/* Don't know how to convert */
*scaledvalue = *scaledlobound = *scaledhibound = 0;
return false;
}
| Datum eqjoinsel | ( | PG_FUNCTION_ARGS | ) |
Definition at line 2133 of file selfuncs.c.
References CLAMP_PROBABILITY, elog, eqjoinsel_inner(), eqjoinsel_semi(), ERROR, find_join_input_rel(), get_commutator(), get_join_variables(), JOIN_ANTI, JOIN_FULL, JOIN_INNER, JOIN_LEFT, JOIN_SEMI, SpecialJoinInfo::jointype, SpecialJoinInfo::min_righthand, PG_GETARG_INT16, PG_GETARG_POINTER, PG_RETURN_FLOAT8, and ReleaseVariableStats.
Referenced by neqjoinsel().
{
PlannerInfo *root = (PlannerInfo *) PG_GETARG_POINTER(0);
Oid operator = PG_GETARG_OID(1);
List *args = (List *) PG_GETARG_POINTER(2);
#ifdef NOT_USED
JoinType jointype = (JoinType) PG_GETARG_INT16(3);
#endif
SpecialJoinInfo *sjinfo = (SpecialJoinInfo *) PG_GETARG_POINTER(4);
double selec;
VariableStatData vardata1;
VariableStatData vardata2;
bool join_is_reversed;
RelOptInfo *inner_rel;
get_join_variables(root, args, sjinfo,
&vardata1, &vardata2, &join_is_reversed);
switch (sjinfo->jointype)
{
case JOIN_INNER:
case JOIN_LEFT:
case JOIN_FULL:
selec = eqjoinsel_inner(operator, &vardata1, &vardata2);
break;
case JOIN_SEMI:
case JOIN_ANTI:
/*
* Look up the join's inner relation. min_righthand is sufficient
* information because neither SEMI nor ANTI joins permit any
* reassociation into or out of their RHS, so the righthand will
* always be exactly that set of rels.
*/
inner_rel = find_join_input_rel(root, sjinfo->min_righthand);
if (!join_is_reversed)
selec = eqjoinsel_semi(operator, &vardata1, &vardata2,
inner_rel);
else
selec = eqjoinsel_semi(get_commutator(operator),
&vardata2, &vardata1,
inner_rel);
break;
default:
/* other values not expected here */
elog(ERROR, "unrecognized join type: %d",
(int) sjinfo->jointype);
selec = 0; /* keep compiler quiet */
break;
}
ReleaseVariableStats(vardata1);
ReleaseVariableStats(vardata2);
CLAMP_PROBABILITY(selec);
PG_RETURN_FLOAT8((float8) selec);
}
| static double eqjoinsel_inner | ( | Oid | operator, | |
| VariableStatData * | vardata1, | |||
| VariableStatData * | vardata2 | |||
| ) | [static] |
Definition at line 2201 of file selfuncs.c.
References VariableStatData::atttype, VariableStatData::atttypmod, CLAMP_PROBABILITY, DatumGetBool, DEFAULT_COLLATION_OID, fmgr_info(), free_attstatsslot(), FunctionCall2Coll(), get_attstatsslot(), get_opcode(), get_variable_numdistinct(), GETSTRUCT, HeapTupleIsValid, i, InvalidOid, NULL, palloc0(), pfree(), STATISTIC_KIND_MCV, and VariableStatData::statsTuple.
Referenced by eqjoinsel().
{
double selec;
double nd1;
double nd2;
bool isdefault1;
bool isdefault2;
Form_pg_statistic stats1 = NULL;
Form_pg_statistic stats2 = NULL;
bool have_mcvs1 = false;
Datum *values1 = NULL;
int nvalues1 = 0;
float4 *numbers1 = NULL;
int nnumbers1 = 0;
bool have_mcvs2 = false;
Datum *values2 = NULL;
int nvalues2 = 0;
float4 *numbers2 = NULL;
int nnumbers2 = 0;
nd1 = get_variable_numdistinct(vardata1, &isdefault1);
nd2 = get_variable_numdistinct(vardata2, &isdefault2);
if (HeapTupleIsValid(vardata1->statsTuple))
{
stats1 = (Form_pg_statistic) GETSTRUCT(vardata1->statsTuple);
have_mcvs1 = get_attstatsslot(vardata1->statsTuple,
vardata1->atttype,
vardata1->atttypmod,
STATISTIC_KIND_MCV,
InvalidOid,
NULL,
&values1, &nvalues1,
&numbers1, &nnumbers1);
}
if (HeapTupleIsValid(vardata2->statsTuple))
{
stats2 = (Form_pg_statistic) GETSTRUCT(vardata2->statsTuple);
have_mcvs2 = get_attstatsslot(vardata2->statsTuple,
vardata2->atttype,
vardata2->atttypmod,
STATISTIC_KIND_MCV,
InvalidOid,
NULL,
&values2, &nvalues2,
&numbers2, &nnumbers2);
}
if (have_mcvs1 && have_mcvs2)
{
/*
* We have most-common-value lists for both relations. Run through
* the lists to see which MCVs actually join to each other with the
* given operator. This allows us to determine the exact join
* selectivity for the portion of the relations represented by the MCV
* lists. We still have to estimate for the remaining population, but
* in a skewed distribution this gives us a big leg up in accuracy.
* For motivation see the analysis in Y. Ioannidis and S.
* Christodoulakis, "On the propagation of errors in the size of join
* results", Technical Report 1018, Computer Science Dept., University
* of Wisconsin, Madison, March 1991 (available from ftp.cs.wisc.edu).
*/
FmgrInfo eqproc;
bool *hasmatch1;
bool *hasmatch2;
double nullfrac1 = stats1->stanullfrac;
double nullfrac2 = stats2->stanullfrac;
double matchprodfreq,
matchfreq1,
matchfreq2,
unmatchfreq1,
unmatchfreq2,
otherfreq1,
otherfreq2,
totalsel1,
totalsel2;
int i,
nmatches;
fmgr_info(get_opcode(operator), &eqproc);
hasmatch1 = (bool *) palloc0(nvalues1 * sizeof(bool));
hasmatch2 = (bool *) palloc0(nvalues2 * sizeof(bool));
/*
* Note we assume that each MCV will match at most one member of the
* other MCV list. If the operator isn't really equality, there could
* be multiple matches --- but we don't look for them, both for speed
* and because the math wouldn't add up...
*/
matchprodfreq = 0.0;
nmatches = 0;
for (i = 0; i < nvalues1; i++)
{
int j;
for (j = 0; j < nvalues2; j++)
{
if (hasmatch2[j])
continue;
if (DatumGetBool(FunctionCall2Coll(&eqproc,
DEFAULT_COLLATION_OID,
values1[i],
values2[j])))
{
hasmatch1[i] = hasmatch2[j] = true;
matchprodfreq += numbers1[i] * numbers2[j];
nmatches++;
break;
}
}
}
CLAMP_PROBABILITY(matchprodfreq);
/* Sum up frequencies of matched and unmatched MCVs */
matchfreq1 = unmatchfreq1 = 0.0;
for (i = 0; i < nvalues1; i++)
{
if (hasmatch1[i])
matchfreq1 += numbers1[i];
else
unmatchfreq1 += numbers1[i];
}
CLAMP_PROBABILITY(matchfreq1);
CLAMP_PROBABILITY(unmatchfreq1);
matchfreq2 = unmatchfreq2 = 0.0;
for (i = 0; i < nvalues2; i++)
{
if (hasmatch2[i])
matchfreq2 += numbers2[i];
else
unmatchfreq2 += numbers2[i];
}
CLAMP_PROBABILITY(matchfreq2);
CLAMP_PROBABILITY(unmatchfreq2);
pfree(hasmatch1);
pfree(hasmatch2);
/*
* Compute total frequency of non-null values that are not in the MCV
* lists.
*/
otherfreq1 = 1.0 - nullfrac1 - matchfreq1 - unmatchfreq1;
otherfreq2 = 1.0 - nullfrac2 - matchfreq2 - unmatchfreq2;
CLAMP_PROBABILITY(otherfreq1);
CLAMP_PROBABILITY(otherfreq2);
/*
* We can estimate the total selectivity from the point of view of
* relation 1 as: the known selectivity for matched MCVs, plus
* unmatched MCVs that are assumed to match against random members of
* relation 2's non-MCV population, plus non-MCV values that are
* assumed to match against random members of relation 2's unmatched
* MCVs plus non-MCV values.
*/
totalsel1 = matchprodfreq;
if (nd2 > nvalues2)
totalsel1 += unmatchfreq1 * otherfreq2 / (nd2 - nvalues2);
if (nd2 > nmatches)
totalsel1 += otherfreq1 * (otherfreq2 + unmatchfreq2) /
(nd2 - nmatches);
/* Same estimate from the point of view of relation 2. */
totalsel2 = matchprodfreq;
if (nd1 > nvalues1)
totalsel2 += unmatchfreq2 * otherfreq1 / (nd1 - nvalues1);
if (nd1 > nmatches)
totalsel2 += otherfreq2 * (otherfreq1 + unmatchfreq1) /
(nd1 - nmatches);
/*
* Use the smaller of the two estimates. This can be justified in
* essentially the same terms as given below for the no-stats case: to
* a first approximation, we are estimating from the point of view of
* the relation with smaller nd.
*/
selec = (totalsel1 < totalsel2) ? totalsel1 : totalsel2;
}
else
{
/*
* We do not have MCV lists for both sides. Estimate the join
* selectivity as MIN(1/nd1,1/nd2)*(1-nullfrac1)*(1-nullfrac2). This
* is plausible if we assume that the join operator is strict and the
* non-null values are about equally distributed: a given non-null
* tuple of rel1 will join to either zero or N2*(1-nullfrac2)/nd2 rows
* of rel2, so total join rows are at most
* N1*(1-nullfrac1)*N2*(1-nullfrac2)/nd2 giving a join selectivity of
* not more than (1-nullfrac1)*(1-nullfrac2)/nd2. By the same logic it
* is not more than (1-nullfrac1)*(1-nullfrac2)/nd1, so the expression
* with MIN() is an upper bound. Using the MIN() means we estimate
* from the point of view of the relation with smaller nd (since the
* larger nd is determining the MIN). It is reasonable to assume that
* most tuples in this rel will have join partners, so the bound is
* probably reasonably tight and should be taken as-is.
*
* XXX Can we be smarter if we have an MCV list for just one side? It
* seems that if we assume equal distribution for the other side, we
* end up with the same answer anyway.
*/
double nullfrac1 = stats1 ? stats1->stanullfrac : 0.0;
double nullfrac2 = stats2 ? stats2->stanullfrac : 0.0;
selec = (1.0 - nullfrac1) * (1.0 - nullfrac2);
if (nd1 > nd2)
selec /= nd1;
else
selec /= nd2;
}
if (have_mcvs1)
free_attstatsslot(vardata1->atttype, values1, nvalues1,
numbers1, nnumbers1);
if (have_mcvs2)
free_attstatsslot(vardata2->atttype, values2, nvalues2,
numbers2, nnumbers2);
return selec;
}
| static double eqjoinsel_semi | ( | Oid | operator, | |
| VariableStatData * | vardata1, | |||
| VariableStatData * | vardata2, | |||
| RelOptInfo * | inner_rel | |||
| ) | [static] |
Definition at line 2427 of file selfuncs.c.
References VariableStatData::atttype, VariableStatData::atttypmod, CLAMP_PROBABILITY, DatumGetBool, DEFAULT_COLLATION_OID, fmgr_info(), free_attstatsslot(), FunctionCall2Coll(), get_attstatsslot(), get_opcode(), get_variable_numdistinct(), GETSTRUCT, HeapTupleIsValid, i, InvalidOid, Min, NULL, OidIsValid, palloc0(), pfree(), VariableStatData::rel, RelOptInfo::rows, STATISTIC_KIND_MCV, and VariableStatData::statsTuple.
Referenced by eqjoinsel().
{
double selec;
double nd1;
double nd2;
bool isdefault1;
bool isdefault2;
Form_pg_statistic stats1 = NULL;
bool have_mcvs1 = false;
Datum *values1 = NULL;
int nvalues1 = 0;
float4 *numbers1 = NULL;
int nnumbers1 = 0;
bool have_mcvs2 = false;
Datum *values2 = NULL;
int nvalues2 = 0;
float4 *numbers2 = NULL;
int nnumbers2 = 0;
nd1 = get_variable_numdistinct(vardata1, &isdefault1);
nd2 = get_variable_numdistinct(vardata2, &isdefault2);
/*
* We clamp nd2 to be not more than what we estimate the inner relation's
* size to be. This is intuitively somewhat reasonable since obviously
* there can't be more than that many distinct values coming from the
* inner rel. The reason for the asymmetry (ie, that we don't clamp nd1
* likewise) is that this is the only pathway by which restriction clauses
* applied to the inner rel will affect the join result size estimate,
* since set_joinrel_size_estimates will multiply SEMI/ANTI selectivity by
* only the outer rel's size. If we clamped nd1 we'd be double-counting
* the selectivity of outer-rel restrictions.
*
* We can apply this clamping both with respect to the base relation from
* which the join variable comes (if there is just one), and to the
* immediate inner input relation of the current join.
*/
if (vardata2->rel)
nd2 = Min(nd2, vardata2->rel->rows);
nd2 = Min(nd2, inner_rel->rows);
if (HeapTupleIsValid(vardata1->statsTuple))
{
stats1 = (Form_pg_statistic) GETSTRUCT(vardata1->statsTuple);
have_mcvs1 = get_attstatsslot(vardata1->statsTuple,
vardata1->atttype,
vardata1->atttypmod,
STATISTIC_KIND_MCV,
InvalidOid,
NULL,
&values1, &nvalues1,
&numbers1, &nnumbers1);
}
if (HeapTupleIsValid(vardata2->statsTuple))
{
have_mcvs2 = get_attstatsslot(vardata2->statsTuple,
vardata2->atttype,
vardata2->atttypmod,
STATISTIC_KIND_MCV,
InvalidOid,
NULL,
&values2, &nvalues2,
&numbers2, &nnumbers2);
}
if (have_mcvs1 && have_mcvs2 && OidIsValid(operator))
{
/*
* We have most-common-value lists for both relations. Run through
* the lists to see which MCVs actually join to each other with the
* given operator. This allows us to determine the exact join
* selectivity for the portion of the relations represented by the MCV
* lists. We still have to estimate for the remaining population, but
* in a skewed distribution this gives us a big leg up in accuracy.
*/
FmgrInfo eqproc;
bool *hasmatch1;
bool *hasmatch2;
double nullfrac1 = stats1->stanullfrac;
double matchfreq1,
uncertainfrac,
uncertain;
int i,
nmatches,
clamped_nvalues2;
/*
* The clamping above could have resulted in nd2 being less than
* nvalues2; in which case, we assume that precisely the nd2 most
* common values in the relation will appear in the join input, and so
* compare to only the first nd2 members of the MCV list. Of course
* this is frequently wrong, but it's the best bet we can make.
*/
clamped_nvalues2 = Min(nvalues2, nd2);
fmgr_info(get_opcode(operator), &eqproc);
hasmatch1 = (bool *) palloc0(nvalues1 * sizeof(bool));
hasmatch2 = (bool *) palloc0(clamped_nvalues2 * sizeof(bool));
/*
* Note we assume that each MCV will match at most one member of the
* other MCV list. If the operator isn't really equality, there could
* be multiple matches --- but we don't look for them, both for speed
* and because the math wouldn't add up...
*/
nmatches = 0;
for (i = 0; i < nvalues1; i++)
{
int j;
for (j = 0; j < clamped_nvalues2; j++)
{
if (hasmatch2[j])
continue;
if (DatumGetBool(FunctionCall2Coll(&eqproc,
DEFAULT_COLLATION_OID,
values1[i],
values2[j])))
{
hasmatch1[i] = hasmatch2[j] = true;
nmatches++;
break;
}
}
}
/* Sum up frequencies of matched MCVs */
matchfreq1 = 0.0;
for (i = 0; i < nvalues1; i++)
{
if (hasmatch1[i])
matchfreq1 += numbers1[i];
}
CLAMP_PROBABILITY(matchfreq1);
pfree(hasmatch1);
pfree(hasmatch2);
/*
* Now we need to estimate the fraction of relation 1 that has at
* least one join partner. We know for certain that the matched MCVs
* do, so that gives us a lower bound, but we're really in the dark
* about everything else. Our crude approach is: if nd1 <= nd2 then
* assume all non-null rel1 rows have join partners, else assume for
* the uncertain rows that a fraction nd2/nd1 have join partners. We
* can discount the known-matched MCVs from the distinct-values counts
* before doing the division.
*
* Crude as the above is, it's completely useless if we don't have
* reliable ndistinct values for both sides. Hence, if either nd1 or
* nd2 is default, punt and assume half of the uncertain rows have
* join partners.
*/
if (!isdefault1 && !isdefault2)
{
nd1 -= nmatches;
nd2 -= nmatches;
if (nd1 <= nd2 || nd2 < 0)
uncertainfrac = 1.0;
else
uncertainfrac = nd2 / nd1;
}
else
uncertainfrac = 0.5;
uncertain = 1.0 - matchfreq1 - nullfrac1;
CLAMP_PROBABILITY(uncertain);
selec = matchfreq1 + uncertainfrac * uncertain;
}
else
{
/*
* Without MCV lists for both sides, we can only use the heuristic
* about nd1 vs nd2.
*/
double nullfrac1 = stats1 ? stats1->stanullfrac : 0.0;
if (!isdefault1 && !isdefault2)
{
if (nd1 <= nd2 || nd2 < 0)
selec = 1.0 - nullfrac1;
else
selec = (nd2 / nd1) * (1.0 - nullfrac1);
}
else
selec = 0.5 * (1.0 - nullfrac1);
}
if (have_mcvs1)
free_attstatsslot(vardata1->atttype, values1, nvalues1,
numbers1, nnumbers1);
if (have_mcvs2)
free_attstatsslot(vardata2->atttype, values2, nvalues2,
numbers2, nnumbers2);
return selec;
}
| Datum eqsel | ( | PG_FUNCTION_ARGS | ) |
Definition at line 216 of file selfuncs.c.
References DEFAULT_EQ_SEL, get_restriction_variable(), IsA, PG_GETARG_INT32, PG_GETARG_POINTER, PG_RETURN_FLOAT8, ReleaseVariableStats, var_eq_const(), and var_eq_non_const().
Referenced by neqsel().
{
PlannerInfo *root = (PlannerInfo *) PG_GETARG_POINTER(0);
Oid operator = PG_GETARG_OID(1);
List *args = (List *) PG_GETARG_POINTER(2);
int varRelid = PG_GETARG_INT32(3);
VariableStatData vardata;
Node *other;
bool varonleft;
double selec;
/*
* If expression is not variable = something or something = variable, then
* punt and return a default estimate.
*/
if (!get_restriction_variable(root, args, varRelid,
&vardata, &other, &varonleft))
PG_RETURN_FLOAT8(DEFAULT_EQ_SEL);
/*
* We can do a lot better if the something is a constant. (Note: the
* Const might result from estimation rather than being a simple constant
* in the query.)
*/
if (IsA(other, Const))
selec = var_eq_const(&vardata, operator,
((Const *) other)->constvalue,
((Const *) other)->constisnull,
varonleft);
else
selec = var_eq_non_const(&vardata, operator, other,
varonleft);
ReleaseVariableStats(vardata);
PG_RETURN_FLOAT8((float8) selec);
}
| int estimate_array_length | ( | Node * | arrayexpr | ) |
Definition at line 2028 of file selfuncs.c.
References ARR_DIMS, ARR_NDIM, ArrayGetNItems(), DatumGetArrayTypeP, IsA, list_length(), and strip_array_coercion().
Referenced by btcostestimate(), cost_qual_eval_walker(), cost_tidscan(), genericcostestimate(), and gincost_scalararrayopexpr().
{
/* look through any binary-compatible relabeling of arrayexpr */
arrayexpr = strip_array_coercion(arrayexpr);
if (arrayexpr && IsA(arrayexpr, Const))
{
Datum arraydatum = ((Const *) arrayexpr)->constvalue;
bool arrayisnull = ((Const *) arrayexpr)->constisnull;
ArrayType *arrayval;
if (arrayisnull)
return 0;
arrayval = DatumGetArrayTypeP(arraydatum);
return ArrayGetNItems(ARR_NDIM(arrayval), ARR_DIMS(arrayval));
}
else if (arrayexpr && IsA(arrayexpr, ArrayExpr) &&
!((ArrayExpr *) arrayexpr)->multidims)
{
return list_length(((ArrayExpr *) arrayexpr)->elements);
}
else
{
/* default guess --- see also scalararraysel */
return 10;
}
}
| Selectivity estimate_hash_bucketsize | ( | PlannerInfo * | root, | |
| Node * | hashkey, | |||
| double | nbuckets | |||
| ) |
Definition at line 3430 of file selfuncs.c.
References VariableStatData::atttype, VariableStatData::atttypmod, examine_variable(), free_attstatsslot(), get_attstatsslot(), get_variable_numdistinct(), GETSTRUCT, HeapTupleIsValid, InvalidOid, NULL, VariableStatData::rel, ReleaseVariableStats, RelOptInfo::rows, STATISTIC_KIND_MCV, VariableStatData::statsTuple, and RelOptInfo::tuples.
Referenced by final_cost_hashjoin().
{
VariableStatData vardata;
double estfract,
ndistinct,
stanullfrac,
mcvfreq,
avgfreq;
bool isdefault;
float4 *numbers;
int nnumbers;
examine_variable(root, hashkey, 0, &vardata);
/* Get number of distinct values */
ndistinct = get_variable_numdistinct(&vardata, &isdefault);
/* If ndistinct isn't real, punt and return 0.1, per comments above */
if (isdefault)
{
ReleaseVariableStats(vardata);
return (Selectivity) 0.1;
}
/* Get fraction that are null */
if (HeapTupleIsValid(vardata.statsTuple))
{
Form_pg_statistic stats;
stats = (Form_pg_statistic) GETSTRUCT(vardata.statsTuple);
stanullfrac = stats->stanullfrac;
}
else
stanullfrac = 0.0;
/* Compute avg freq of all distinct data values in raw relation */
avgfreq = (1.0 - stanullfrac) / ndistinct;
/*
* Adjust ndistinct to account for restriction clauses. Observe we are
* assuming that the data distribution is affected uniformly by the
* restriction clauses!
*
* XXX Possibly better way, but much more expensive: multiply by
* selectivity of rel's restriction clauses that mention the target Var.
*/
if (vardata.rel)
ndistinct *= vardata.rel->rows / vardata.rel->tuples;
/*
* Initial estimate of bucketsize fraction is 1/nbuckets as long as the
* number of buckets is less than the expected number of distinct values;
* otherwise it is 1/ndistinct.
*/
if (ndistinct > nbuckets)
estfract = 1.0 / nbuckets;
else
estfract = 1.0 / ndistinct;
/*
* Look up the frequency of the most common value, if available.
*/
mcvfreq = 0.0;
if (HeapTupleIsValid(vardata.statsTuple))
{
if (get_attstatsslot(vardata.statsTuple,
vardata.atttype, vardata.atttypmod,
STATISTIC_KIND_MCV, InvalidOid,
NULL,
NULL, NULL,
&numbers, &nnumbers))
{
/*
* The first MCV stat is for the most common value.
*/
if (nnumbers > 0)
mcvfreq = numbers[0];
free_attstatsslot(vardata.atttype, NULL, 0,
numbers, nnumbers);
}
}
/*
* Adjust estimated bucketsize upward to account for skewed distribution.
*/
if (avgfreq > 0.0 && mcvfreq > avgfreq)
estfract *= mcvfreq / avgfreq;
/*
* Clamp bucketsize to sane range (the above adjustment could easily
* produce an out-of-range result). We set the lower bound a little above
* zero, since zero isn't a very sane result.
*/
if (estfract < 1.0e-6)
estfract = 1.0e-6;
else if (estfract > 1.0)
estfract = 1.0;
ReleaseVariableStats(vardata);
return (Selectivity) estfract;
}
| double estimate_num_groups | ( | PlannerInfo * | root, | |
| List * | groupExprs, | |||
| double | input_rows | |||
| ) |
Definition at line 3206 of file selfuncs.c.
References add_unique_group_var(), Assert, contain_volatile_functions(), examine_variable(), exprType(), for_each_cell, HeapTupleIsValid, VariableStatData::isunique, lcons(), lfirst, linitial, list_head(), lnext, GroupVarInfo::ndistinct, NIL, pull_var_clause(), PVC_RECURSE_AGGREGATES, PVC_RECURSE_PLACEHOLDERS, GroupVarInfo::rel, ReleaseVariableStats, RELOPT_BASEREL, RelOptInfo::reloptkind, RelOptInfo::rows, VariableStatData::statsTuple, and RelOptInfo::tuples.
Referenced by create_unique_path(), query_planner(), and recurse_set_operations().
{
List *varinfos = NIL;
double numdistinct;
ListCell *l;
/*
* If no grouping columns, there's exactly one group. (This can't happen
* for normal cases with GROUP BY or DISTINCT, but it is possible for
* corner cases with set operations.)
*/
if (groupExprs == NIL)
return 1.0;
/*
* Count groups derived from boolean grouping expressions. For other
* expressions, find the unique Vars used, treating an expression as a Var
* if we can find stats for it. For each one, record the statistical
* estimate of number of distinct values (total in its table, without
* regard for filtering).
*/
numdistinct = 1.0;
foreach(l, groupExprs)
{
Node *groupexpr = (Node *) lfirst(l);
VariableStatData vardata;
List *varshere;
ListCell *l2;
/* Short-circuit for expressions returning boolean */
if (exprType(groupexpr) == BOOLOID)
{
numdistinct *= 2.0;
continue;
}
/*
* If examine_variable is able to deduce anything about the GROUP BY
* expression, treat it as a single variable even if it's really more
* complicated.
*/
examine_variable(root, groupexpr, 0, &vardata);
if (HeapTupleIsValid(vardata.statsTuple) || vardata.isunique)
{
varinfos = add_unique_group_var(root, varinfos,
groupexpr, &vardata);
ReleaseVariableStats(vardata);
continue;
}
ReleaseVariableStats(vardata);
/*
* Else pull out the component Vars. Handle PlaceHolderVars by
* recursing into their arguments (effectively assuming that the
* PlaceHolderVar doesn't change the number of groups, which boils
* down to ignoring the possible addition of nulls to the result set).
*/
varshere = pull_var_clause(groupexpr,
PVC_RECURSE_AGGREGATES,
PVC_RECURSE_PLACEHOLDERS);
/*
* If we find any variable-free GROUP BY item, then either it is a
* constant (and we can ignore it) or it contains a volatile function;
* in the latter case we punt and assume that each input row will
* yield a distinct group.
*/
if (varshere == NIL)
{
if (contain_volatile_functions(groupexpr))
return input_rows;
continue;
}
/*
* Else add variables to varinfos list
*/
foreach(l2, varshere)
{
Node *var = (Node *) lfirst(l2);
examine_variable(root, var, 0, &vardata);
varinfos = add_unique_group_var(root, varinfos, var, &vardata);
ReleaseVariableStats(vardata);
}
}
/*
* If now no Vars, we must have an all-constant or all-boolean GROUP BY
* list.
*/
if (varinfos == NIL)
{
/* Guard against out-of-range answers */
if (numdistinct > input_rows)
numdistinct = input_rows;
return numdistinct;
}
/*
* Group Vars by relation and estimate total numdistinct.
*
* For each iteration of the outer loop, we process the frontmost Var in
* varinfos, plus all other Vars in the same relation. We remove these
* Vars from the newvarinfos list for the next iteration. This is the
* easiest way to group Vars of same rel together.
*/
do
{
GroupVarInfo *varinfo1 = (GroupVarInfo *) linitial(varinfos);
RelOptInfo *rel = varinfo1->rel;
double reldistinct = varinfo1->ndistinct;
double relmaxndistinct = reldistinct;
int relvarcount = 1;
List *newvarinfos = NIL;
/*
* Get the product of numdistinct estimates of the Vars for this rel.
* Also, construct new varinfos list of remaining Vars.
*/
for_each_cell(l, lnext(list_head(varinfos)))
{
GroupVarInfo *varinfo2 = (GroupVarInfo *) lfirst(l);
if (varinfo2->rel == varinfo1->rel)
{
reldistinct *= varinfo2->ndistinct;
if (relmaxndistinct < varinfo2->ndistinct)
relmaxndistinct = varinfo2->ndistinct;
relvarcount++;
}
else
{
/* not time to process varinfo2 yet */
newvarinfos = lcons(varinfo2, newvarinfos);
}
}
/*
* Sanity check --- don't divide by zero if empty relation.
*/
Assert(rel->reloptkind == RELOPT_BASEREL);
if (rel->tuples > 0)
{
/*
* Clamp to size of rel, or size of rel / 10 if multiple Vars. The
* fudge factor is because the Vars are probably correlated but we
* don't know by how much. We should never clamp to less than the
* largest ndistinct value for any of the Vars, though, since
* there will surely be at least that many groups.
*/
double clamp = rel->tuples;
if (relvarcount > 1)
{
clamp *= 0.1;
if (clamp < relmaxndistinct)
{
clamp = relmaxndistinct;
/* for sanity in case some ndistinct is too large: */
if (clamp > rel->tuples)
clamp = rel->tuples;
}
}
if (reldistinct > clamp)
reldistinct = clamp;
/*
* Multiply by restriction selectivity.
*/
reldistinct *= rel->rows / rel->tuples;
/*
* Update estimate of total distinct groups.
*/
numdistinct *= reldistinct;
}
varinfos = newvarinfos;
} while (varinfos != NIL);
numdistinct = ceil(numdistinct);
/* Guard against out-of-range answers */
if (numdistinct > input_rows)
numdistinct = input_rows;
if (numdistinct < 1.0)
numdistinct = 1.0;
return numdistinct;
}
| static void examine_simple_variable | ( | PlannerInfo * | root, | |
| Var * | var, | |||
| VariableStatData * | vardata | |||
| ) | [static] |
Definition at line 4462 of file selfuncs.c.
References Alias::aliasname, Assert, BoolGetDatum, Query::distinctClause, elog, RangeTblEntry::eref, ERROR, TargetEntry::expr, find_base_rel(), VariableStatData::freefunc, get_relation_stats_hook, get_tle_by_resno(), Query::groupClause, HeapTupleIsValid, RangeTblEntry::inh, Int16GetDatum, InvalidOid, IsA, VariableStatData::isunique, list_length(), NULL, ObjectIdGetDatum, PlannerInfo::parse, RangeTblEntry::relid, TargetEntry::resjunk, RTE_RELATION, RTE_SUBQUERY, RangeTblEntry::rtekind, SearchSysCache3, RangeTblEntry::security_barrier, Query::setOperations, PlannerInfo::simple_rte_array, STATRELATTINH, VariableStatData::statsTuple, RangeTblEntry::subquery, RelOptInfo::subroot, targetIsInSortList(), Query::targetList, Var::varattno, Var::varlevelsup, and Var::varno.
Referenced by examine_variable().
{
RangeTblEntry *rte = root->simple_rte_array[var->varno];
Assert(IsA(rte, RangeTblEntry));
if (get_relation_stats_hook &&
(*get_relation_stats_hook) (root, rte, var->varattno, vardata))
{
/*
* The hook took control of acquiring a stats tuple. If it did supply
* a tuple, it'd better have supplied a freefunc.
*/
if (HeapTupleIsValid(vardata->statsTuple) &&
!vardata->freefunc)
elog(ERROR, "no function provided to release variable stats with");
}
else if (rte->rtekind == RTE_RELATION)
{
/*
* Plain table or parent of an inheritance appendrel, so look up the
* column in pg_statistic
*/
vardata->statsTuple = SearchSysCache3(STATRELATTINH,
ObjectIdGetDatum(rte->relid),
Int16GetDatum(var->varattno),
BoolGetDatum(rte->inh));
vardata->freefunc = ReleaseSysCache;
}
else if (rte->rtekind == RTE_SUBQUERY && !rte->inh)
{
/*
* Plain subquery (not one that was converted to an appendrel).
*/
Query *subquery = rte->subquery;
RelOptInfo *rel;
TargetEntry *ste;
/*
* Punt if subquery uses set operations or GROUP BY, as these will
* mash underlying columns' stats beyond recognition. (Set ops are
* particularly nasty; if we forged ahead, we would return stats
* relevant to only the leftmost subselect...) DISTINCT is also
* problematic, but we check that later because there is a possibility
* of learning something even with it.
*/
if (subquery->setOperations ||
subquery->groupClause)
return;
/*
* OK, fetch RelOptInfo for subquery. Note that we don't change the
* rel returned in vardata, since caller expects it to be a rel of the
* caller's query level. Because we might already be recursing, we
* can't use that rel pointer either, but have to look up the Var's
* rel afresh.
*/
rel = find_base_rel(root, var->varno);
/* If the subquery hasn't been planned yet, we have to punt */
if (rel->subroot == NULL)
return;
Assert(IsA(rel->subroot, PlannerInfo));
/*
* Switch our attention to the subquery as mangled by the planner. It
* was okay to look at the pre-planning version for the tests above,
* but now we need a Var that will refer to the subroot's live
* RelOptInfos. For instance, if any subquery pullup happened during
* planning, Vars in the targetlist might have gotten replaced, and we
* need to see the replacement expressions.
*/
subquery = rel->subroot->parse;
Assert(IsA(subquery, Query));
/* Get the subquery output expression referenced by the upper Var */
ste = get_tle_by_resno(subquery->targetList, var->varattno);
if (ste == NULL || ste->resjunk)
elog(ERROR, "subquery %s does not have attribute %d",
rte->eref->aliasname, var->varattno);
var = (Var *) ste->expr;
/*
* If subquery uses DISTINCT, we can't make use of any stats for the
* variable ... but, if it's the only DISTINCT column, we are entitled
* to consider it unique. We do the test this way so that it works
* for cases involving DISTINCT ON.
*/
if (subquery->distinctClause)
{
if (list_length(subquery->distinctClause) == 1 &&
targetIsInSortList(ste, InvalidOid, subquery->distinctClause))
vardata->isunique = true;
/* cannot go further */
return;
}
/*
* If the sub-query originated from a view with the security_barrier
* attribute, we must not look at the variable's statistics, though it
* seems all right to notice the existence of a DISTINCT clause. So
* stop here.
*
* This is probably a harsher restriction than necessary; it's
* certainly OK for the selectivity estimator (which is a C function,
* and therefore omnipotent anyway) to look at the statistics. But
* many selectivity estimators will happily *invoke the operator
* function* to try to work out a good estimate - and that's not OK.
* So for now, don't dig down for stats.
*/
if (rte->security_barrier)
return;
/* Can only handle a simple Var of subquery's query level */
if (var && IsA(var, Var) &&
var->varlevelsup == 0)
{
/*
* OK, recurse into the subquery. Note that the original setting
* of vardata->isunique (which will surely be false) is left
* unchanged in this situation. That's what we want, since even
* if the underlying column is unique, the subquery may have
* joined to other tables in a way that creates duplicates.
*/
examine_simple_variable(rel->subroot, var, vardata);
}
}
else
{
/*
* Otherwise, the Var comes from a FUNCTION, VALUES, or CTE RTE. (We
* won't see RTE_JOIN here because join alias Vars have already been
* flattened.) There's not much we can do with function outputs, but
* maybe someday try to be smarter about VALUES and/or CTEs.
*/
}
}
| void examine_variable | ( | PlannerInfo * | root, | |
| Node * | node, | |||
| int | varRelid, | |||
| VariableStatData * | vardata | |||
| ) |
Definition at line 4275 of file selfuncs.c.
References arg, VariableStatData::atttype, VariableStatData::atttypmod, BMS_EMPTY_SET, bms_free(), bms_is_member(), bms_membership(), BMS_MULTIPLE, BMS_SINGLETON, bms_singleton_member(), BoolGetDatum, elog, equal(), ERROR, examine_simple_variable(), exprType(), exprTypmod(), find_base_rel(), find_join_rel(), VariableStatData::freefunc, get_index_stats_hook, has_unique_index(), HeapTupleIsValid, IndexOptInfo::indexkeys, RelOptInfo::indexlist, IndexOptInfo::indexoid, IndexOptInfo::indexprs, IndexOptInfo::indpred, Int16GetDatum, IsA, VariableStatData::isunique, lfirst, list_head(), lnext, MemSet, IndexOptInfo::ncolumns, NIL, NULL, ObjectIdGetDatum, IndexOptInfo::predOK, pull_varnos(), VariableStatData::rel, SearchSysCache3, STATRELATTINH, VariableStatData::statsTuple, IndexOptInfo::unique, VariableStatData::var, Var::varattno, Var::varno, Var::vartype, VariableStatData::vartype, and Var::vartypmod.
Referenced by booltestsel(), estimate_hash_bucketsize(), estimate_num_groups(), get_join_variables(), get_restriction_variable(), mergejoinscansel(), nulltestsel(), and scalararraysel_containment().
{
Node *basenode;
Relids varnos;
RelOptInfo *onerel;
/* Make sure we don't return dangling pointers in vardata */
MemSet(vardata, 0, sizeof(VariableStatData));
/* Save the exposed type of the expression */
vardata->vartype = exprType(node);
/* Look inside any binary-compatible relabeling */
if (IsA(node, RelabelType))
basenode = (Node *) ((RelabelType *) node)->arg;
else
basenode = node;
/* Fast path for a simple Var */
if (IsA(basenode, Var) &&
(varRelid == 0 || varRelid == ((Var *) basenode)->varno))
{
Var *var = (Var *) basenode;
/* Set up result fields other than the stats tuple */
vardata->var = basenode; /* return Var without relabeling */
vardata->rel = find_base_rel(root, var->varno);
vardata->atttype = var->vartype;
vardata->atttypmod = var->vartypmod;
vardata->isunique = has_unique_index(vardata->rel, var->varattno);
/* Try to locate some stats */
examine_simple_variable(root, var, vardata);
return;
}
/*
* Okay, it's a more complicated expression. Determine variable
* membership. Note that when varRelid isn't zero, only vars of that
* relation are considered "real" vars.
*/
varnos = pull_varnos(basenode);
onerel = NULL;
switch (bms_membership(varnos))
{
case BMS_EMPTY_SET:
/* No Vars at all ... must be pseudo-constant clause */
break;
case BMS_SINGLETON:
if (varRelid == 0 || bms_is_member(varRelid, varnos))
{
onerel = find_base_rel(root,
(varRelid ? varRelid : bms_singleton_member(varnos)));
vardata->rel = onerel;
node = basenode; /* strip any relabeling */
}
/* else treat it as a constant */
break;
case BMS_MULTIPLE:
if (varRelid == 0)
{
/* treat it as a variable of a join relation */
vardata->rel = find_join_rel(root, varnos);
node = basenode; /* strip any relabeling */
}
else if (bms_is_member(varRelid, varnos))
{
/* ignore the vars belonging to other relations */
vardata->rel = find_base_rel(root, varRelid);
node = basenode; /* strip any relabeling */
/* note: no point in expressional-index search here */
}
/* else treat it as a constant */
break;
}
bms_free(varnos);
vardata->var = node;
vardata->atttype = exprType(node);
vardata->atttypmod = exprTypmod(node);
if (onerel)
{
/*
* We have an expression in vars of a single relation. Try to match
* it to expressional index columns, in hopes of finding some
* statistics.
*
* XXX it's conceivable that there are multiple matches with different
* index opfamilies; if so, we need to pick one that matches the
* operator we are estimating for. FIXME later.
*/
ListCell *ilist;
foreach(ilist, onerel->indexlist)
{
IndexOptInfo *index = (IndexOptInfo *) lfirst(ilist);
ListCell *indexpr_item;
int pos;
indexpr_item = list_head(index->indexprs);
if (indexpr_item == NULL)
continue; /* no expressions here... */
for (pos = 0; pos < index->ncolumns; pos++)
{
if (index->indexkeys[pos] == 0)
{
Node *indexkey;
if (indexpr_item == NULL)
elog(ERROR, "too few entries in indexprs list");
indexkey = (Node *) lfirst(indexpr_item);
if (indexkey && IsA(indexkey, RelabelType))
indexkey = (Node *) ((RelabelType *) indexkey)->arg;
if (equal(node, indexkey))
{
/*
* Found a match ... is it a unique index? Tests here
* should match has_unique_index().
*/
if (index->unique &&
index->ncolumns == 1 &&
(index->indpred == NIL || index->predOK))
vardata->isunique = true;
/*
* Has it got stats? We only consider stats for
* non-partial indexes, since partial indexes probably
* don't reflect whole-relation statistics; the above
* check for uniqueness is the only info we take from
* a partial index.
*
* An index stats hook, however, must make its own
* decisions about what to do with partial indexes.
*/
if (get_index_stats_hook &&
(*get_index_stats_hook) (root, index->indexoid,
pos + 1, vardata))
{
/*
* The hook took control of acquiring a stats
* tuple. If it did supply a tuple, it'd better
* have supplied a freefunc.
*/
if (HeapTupleIsValid(vardata->statsTuple) &&
!vardata->freefunc)
elog(ERROR, "no function provided to release variable stats with");
}
else if (index->indpred == NIL)
{
vardata->statsTuple =
SearchSysCache3(STATRELATTINH,
ObjectIdGetDatum(index->indexoid),
Int16GetDatum(pos + 1),
BoolGetDatum(false));
vardata->freefunc = ReleaseSysCache;
}
if (vardata->statsTuple)
break;
}
indexpr_item = lnext(indexpr_item);
}
}
if (vardata->statsTuple)
break;
}
}
}
| static int find_index_column | ( | Node * | op, | |
| IndexOptInfo * | index | |||
| ) | [static] |
Definition at line 6725 of file selfuncs.c.
References i, match_index_to_operand(), and IndexOptInfo::ncolumns.
Referenced by gincost_opexpr(), and gincost_scalararrayopexpr().
{
int i;
for (i = 0; i < index->ncolumns; i++)
{
if (match_index_to_operand(op, i, index))
return i;
}
return -1;
}
| static RelOptInfo * find_join_input_rel | ( | PlannerInfo * | root, | |
| Relids | relids | |||
| ) | [static] |
Definition at line 5072 of file selfuncs.c.
References BMS_EMPTY_SET, bms_membership(), BMS_MULTIPLE, BMS_SINGLETON, bms_singleton_member(), elog, ERROR, find_base_rel(), find_join_rel(), and NULL.
Referenced by eqjoinsel().
{
RelOptInfo *rel = NULL;
switch (bms_membership(relids))
{
case BMS_EMPTY_SET:
/* should not happen */
break;
case BMS_SINGLETON:
rel = find_base_rel(root, bms_singleton_member(relids));
break;
case BMS_MULTIPLE:
rel = find_join_rel(root, relids);
break;
}
if (rel == NULL)
elog(ERROR, "could not find RelOptInfo for given relids");
return rel;
}
| static void genericcostestimate | ( | PlannerInfo * | root, | |
| IndexPath * | path, | |||
| double | loop_count, | |||
| GenericCosts * | costs | |||
| ) | [static] |
Definition at line 5948 of file selfuncs.c.
References add_predicate_to_quals(), ScalarArrayOpExpr::args, RestrictInfo::clause, clauselist_selectivity(), cost_qual_eval(), cpu_index_tuple_cost, cpu_operator_cost, estimate_array_length(), get_tablespace_page_costs(), index_pages_fetched(), GenericCosts::indexCorrelation, IndexPath::indexinfo, IndexPath::indexorderbys, IndexPath::indexquals, GenericCosts::indexSelectivity, GenericCosts::indexStartupCost, GenericCosts::indexTotalCost, IsA, JOIN_INNER, lfirst, list_length(), lsecond, NULL, GenericCosts::num_sa_scans, GenericCosts::numIndexPages, GenericCosts::numIndexTuples, IndexOptInfo::pages, QualCost::per_tuple, IndexOptInfo::rel, RelOptInfo::relid, IndexOptInfo::reltablespace, rint(), GenericCosts::spc_random_page_cost, QualCost::startup, IndexOptInfo::tuples, and RelOptInfo::tuples.
Referenced by btcostestimate(), gistcostestimate(), hashcostestimate(), and spgcostestimate().
{
IndexOptInfo *index = path->indexinfo;
List *indexQuals = path->indexquals;
List *indexOrderBys = path->indexorderbys;
Cost indexStartupCost;
Cost indexTotalCost;
Selectivity indexSelectivity;
double indexCorrelation;
double numIndexPages;
double numIndexTuples;
double spc_random_page_cost;
double num_sa_scans;
double num_outer_scans;
double num_scans;
QualCost index_qual_cost;
double qual_op_cost;
double qual_arg_cost;
List *selectivityQuals;
ListCell *l;
/*
* If the index is partial, AND the index predicate with the explicitly
* given indexquals to produce a more accurate idea of the index
* selectivity.
*/
selectivityQuals = add_predicate_to_quals(index, indexQuals);
/*
* Check for ScalarArrayOpExpr index quals, and estimate the number of
* index scans that will be performed.
*/
num_sa_scans = 1;
foreach(l, indexQuals)
{
RestrictInfo *rinfo = (RestrictInfo *) lfirst(l);
if (IsA(rinfo->clause, ScalarArrayOpExpr))
{
ScalarArrayOpExpr *saop = (ScalarArrayOpExpr *) rinfo->clause;
int alength = estimate_array_length(lsecond(saop->args));
if (alength > 1)
num_sa_scans *= alength;
}
}
/* Estimate the fraction of main-table tuples that will be visited */
indexSelectivity = clauselist_selectivity(root, selectivityQuals,
index->rel->relid,
JOIN_INNER,
NULL);
/*
* If caller didn't give us an estimate, estimate the number of index
* tuples that will be visited. We do it in this rather peculiar-looking
* way in order to get the right answer for partial indexes.
*/
numIndexTuples = costs->numIndexTuples;
if (numIndexTuples <= 0.0)
{
numIndexTuples = indexSelectivity * index->rel->tuples;
/*
* The above calculation counts all the tuples visited across all
* scans induced by ScalarArrayOpExpr nodes. We want to consider the
* average per-indexscan number, so adjust. This is a handy place to
* round to integer, too. (If caller supplied tuple estimate, it's
* responsible for handling these considerations.)
*/
numIndexTuples = rint(numIndexTuples / num_sa_scans);
}
/*
* We can bound the number of tuples by the index size in any case. Also,
* always estimate at least one tuple is touched, even when
* indexSelectivity estimate is tiny.
*/
if (numIndexTuples > index->tuples)
numIndexTuples = index->tuples;
if (numIndexTuples < 1.0)
numIndexTuples = 1.0;
/*
* Estimate the number of index pages that will be retrieved.
*
* We use the simplistic method of taking a pro-rata fraction of the total
* number of index pages. In effect, this counts only leaf pages and not
* any overhead such as index metapage or upper tree levels.
*
* In practice access to upper index levels is often nearly free because
* those tend to stay in cache under load; moreover, the cost involved is
* highly dependent on index type. We therefore ignore such costs here
* and leave it to the caller to add a suitable charge if needed.
*/
if (index->pages > 1 && index->tuples > 1)
numIndexPages = ceil(numIndexTuples * index->pages / index->tuples);
else
numIndexPages = 1.0;
/* fetch estimated page cost for schema containing index */
get_tablespace_page_costs(index->reltablespace,
&spc_random_page_cost,
NULL);
/*
* Now compute the disk access costs.
*
* The above calculations are all per-index-scan. However, if we are in a
* nestloop inner scan, we can expect the scan to be repeated (with
* different search keys) for each row of the outer relation. Likewise,
* ScalarArrayOpExpr quals result in multiple index scans. This creates
* the potential for cache effects to reduce the number of disk page
* fetches needed. We want to estimate the average per-scan I/O cost in
* the presence of caching.
*
* We use the Mackert-Lohman formula (see costsize.c for details) to
* estimate the total number of page fetches that occur. While this
* wasn't what it was designed for, it seems a reasonable model anyway.
* Note that we are counting pages not tuples anymore, so we take N = T =
* index size, as if there were one "tuple" per page.
*/
num_outer_scans = loop_count;
num_scans = num_sa_scans * num_outer_scans;
if (num_scans > 1)
{
double pages_fetched;
/* total page fetches ignoring cache effects */
pages_fetched = numIndexPages * num_scans;
/* use Mackert and Lohman formula to adjust for cache effects */
pages_fetched = index_pages_fetched(pages_fetched,
index->pages,
(double) index->pages,
root);
/*
* Now compute the total disk access cost, and then report a pro-rated
* share for each outer scan. (Don't pro-rate for ScalarArrayOpExpr,
* since that's internal to the indexscan.)
*/
indexTotalCost = (pages_fetched * spc_random_page_cost)
/ num_outer_scans;
}
else
{
/*
* For a single index scan, we just charge spc_random_page_cost per
* page touched.
*/
indexTotalCost = numIndexPages * spc_random_page_cost;
}
/*
* CPU cost: any complex expressions in the indexquals will need to be
* evaluated once at the start of the scan to reduce them to runtime keys
* to pass to the index AM (see nodeIndexscan.c). We model the per-tuple
* CPU costs as cpu_index_tuple_cost plus one cpu_operator_cost per
* indexqual operator. Because we have numIndexTuples as a per-scan
* number, we have to multiply by num_sa_scans to get the correct result
* for ScalarArrayOpExpr cases. Similarly add in costs for any index
* ORDER BY expressions.
*
* Note: this neglects the possible costs of rechecking lossy operators.
* Detecting that that might be needed seems more expensive than it's
* worth, though, considering all the other inaccuracies here ...
*/
cost_qual_eval(&index_qual_cost, indexQuals, root);
qual_arg_cost = index_qual_cost.startup + index_qual_cost.per_tuple;
cost_qual_eval(&index_qual_cost, indexOrderBys, root);
qual_arg_cost += index_qual_cost.startup + index_qual_cost.per_tuple;
qual_op_cost = cpu_operator_cost *
(list_length(indexQuals) + list_length(indexOrderBys));
qual_arg_cost -= qual_op_cost;
if (qual_arg_cost < 0) /* just in case... */
qual_arg_cost = 0;
indexStartupCost = qual_arg_cost;
indexTotalCost += qual_arg_cost;
indexTotalCost += numIndexTuples * num_sa_scans * (cpu_index_tuple_cost + qual_op_cost);
/*
* Generic assumption about index correlation: there isn't any.
*/
indexCorrelation = 0.0;
/*
* Return everything to caller.
*/
costs->indexStartupCost = indexStartupCost;
costs->indexTotalCost = indexTotalCost;
costs->indexSelectivity = indexSelectivity;
costs->indexCorrelation = indexCorrelation;
costs->numIndexPages = numIndexPages;
costs->numIndexTuples = numIndexTuples;
costs->spc_random_page_cost = spc_random_page_cost;
costs->num_sa_scans = num_sa_scans;
}
| static bool get_actual_variable_range | ( | PlannerInfo * | root, | |
| VariableStatData * | vardata, | |||
| Oid | sortop, | |||
| Datum * | min, | |||
| Datum * | max | |||
| ) | [static] |
Definition at line 4863 of file selfuncs.c.
References AccessShareLock, Assert, VariableStatData::atttype, BTGreaterStrategyNumber, BTLessStrategyNumber, BTREE_AM_OID, BuildIndexInfo(), CreateExecutorState(), datumCopy(), ExprContext::ecxt_per_tuple_memory, ExprContext::ecxt_scantuple, elog, ERROR, ExecDropSingleTupleTableSlot(), ExecStoreTuple(), FormIndexDatum(), FreeExecutorState(), get_op_opfamily_strategy(), get_typlenbyval(), GetPerTupleExprContext, heap_close, heap_open(), IndexOptInfo::hypothetical, index_beginscan(), index_close(), index_endscan(), index_getnext(), index_open(), index_rescan(), RelOptInfo::indexlist, IndexOptInfo::indexoid, IndexOptInfo::indpred, InvalidBuffer, InvalidOid, InvalidStrategy, lfirst, MakeSingleTupleTableSlot(), match_index_to_operand(), MemoryContextSwitchTo(), NIL, NoLock, NULL, VariableStatData::rel, IndexOptInfo::relam, RelationGetDescr, RelationGetRelationName, RangeTblEntry::relid, RelOptInfo::relid, IndexOptInfo::reverse_sort, RTE_RELATION, RangeTblEntry::rtekind, ScanKeyEntryInitialize(), PlannerInfo::simple_rte_array, SK_ISNULL, SK_SEARCHNOTNULL, SnapshotNow, IndexOptInfo::sortopfamily, values, and VariableStatData::var.
Referenced by get_variable_range(), and ineq_histogram_selectivity().
{
bool have_data = false;
RelOptInfo *rel = vardata->rel;
RangeTblEntry *rte;
ListCell *lc;
/* No hope if no relation or it doesn't have indexes */
if (rel == NULL || rel->indexlist == NIL)
return false;
/* If it has indexes it must be a plain relation */
rte = root->simple_rte_array[rel->relid];
Assert(rte->rtekind == RTE_RELATION);
/* Search through the indexes to see if any match our problem */
foreach(lc, rel->indexlist)
{
IndexOptInfo *index = (IndexOptInfo *) lfirst(lc);
ScanDirection indexscandir;
/* Ignore non-btree indexes */
if (index->relam != BTREE_AM_OID)
continue;
/*
* Ignore partial indexes --- we only want stats that cover the entire
* relation.
*/
if (index->indpred != NIL)
continue;
/*
* The index list might include hypothetical indexes inserted by a
* get_relation_info hook --- don't try to access them.
*/
if (index->hypothetical)
continue;
/*
* The first index column must match the desired variable and sort
* operator --- but we can use a descending-order index.
*/
if (!match_index_to_operand(vardata->var, 0, index))
continue;
switch (get_op_opfamily_strategy(sortop, index->sortopfamily[0]))
{
case BTLessStrategyNumber:
if (index->reverse_sort[0])
indexscandir = BackwardScanDirection;
else
indexscandir = ForwardScanDirection;
break;
case BTGreaterStrategyNumber:
if (index->reverse_sort[0])
indexscandir = ForwardScanDirection;
else
indexscandir = BackwardScanDirection;
break;
default:
/* index doesn't match the sortop */
continue;
}
/*
* Found a suitable index to extract data from. We'll need an EState
* and a bunch of other infrastructure.
*/
{
EState *estate;
ExprContext *econtext;
MemoryContext tmpcontext;
MemoryContext oldcontext;
Relation heapRel;
Relation indexRel;
IndexInfo *indexInfo;
TupleTableSlot *slot;
int16 typLen;
bool typByVal;
ScanKeyData scankeys[1];
IndexScanDesc index_scan;
HeapTuple tup;
Datum values[INDEX_MAX_KEYS];
bool isnull[INDEX_MAX_KEYS];
estate = CreateExecutorState();
econtext = GetPerTupleExprContext(estate);
/* Make sure any cruft is generated in the econtext's memory */
tmpcontext = econtext->ecxt_per_tuple_memory;
oldcontext = MemoryContextSwitchTo(tmpcontext);
/*
* Open the table and index so we can read from them. We should
* already have at least AccessShareLock on the table, but not
* necessarily on the index.
*/
heapRel = heap_open(rte->relid, NoLock);
indexRel = index_open(index->indexoid, AccessShareLock);
/* extract index key information from the index's pg_index info */
indexInfo = BuildIndexInfo(indexRel);
/* some other stuff */
slot = MakeSingleTupleTableSlot(RelationGetDescr(heapRel));
econtext->ecxt_scantuple = slot;
get_typlenbyval(vardata->atttype, &typLen, &typByVal);
/* set up an IS NOT NULL scan key so that we ignore nulls */
ScanKeyEntryInitialize(&scankeys[0],
SK_ISNULL | SK_SEARCHNOTNULL,
1, /* index col to scan */
InvalidStrategy, /* no strategy */
InvalidOid, /* no strategy subtype */
InvalidOid, /* no collation */
InvalidOid, /* no reg proc for this */
(Datum) 0); /* constant */
have_data = true;
/* If min is requested ... */
if (min)
{
index_scan = index_beginscan(heapRel, indexRel, SnapshotNow,
1, 0);
index_rescan(index_scan, scankeys, 1, NULL, 0);
/* Fetch first tuple in sortop's direction */
if ((tup = index_getnext(index_scan,
indexscandir)) != NULL)
{
/* Extract the index column values from the heap tuple */
ExecStoreTuple(tup, slot, InvalidBuffer, false);
FormIndexDatum(indexInfo, slot, estate,
values, isnull);
/* Shouldn't have got a null, but be careful */
if (isnull[0])
elog(ERROR, "found unexpected null value in index \"%s\"",
RelationGetRelationName(indexRel));
/* Copy the index column value out to caller's context */
MemoryContextSwitchTo(oldcontext);
*min = datumCopy(values[0], typByVal, typLen);
MemoryContextSwitchTo(tmpcontext);
}
else
have_data = false;
index_endscan(index_scan);
}
/* If max is requested, and we didn't find the index is empty */
if (max && have_data)
{
index_scan = index_beginscan(heapRel, indexRel, SnapshotNow,
1, 0);
index_rescan(index_scan, scankeys, 1, NULL, 0);
/* Fetch first tuple in reverse direction */
if ((tup = index_getnext(index_scan,
-indexscandir)) != NULL)
{
/* Extract the index column values from the heap tuple */
ExecStoreTuple(tup, slot, InvalidBuffer, false);
FormIndexDatum(indexInfo, slot, estate,
values, isnull);
/* Shouldn't have got a null, but be careful */
if (isnull[0])
elog(ERROR, "found unexpected null value in index \"%s\"",
RelationGetRelationName(indexRel));
/* Copy the index column value out to caller's context */
MemoryContextSwitchTo(oldcontext);
*max = datumCopy(values[0], typByVal, typLen);
MemoryContextSwitchTo(tmpcontext);
}
else
have_data = false;
index_endscan(index_scan);
}
/* Clean everything up */
ExecDropSingleTupleTableSlot(slot);
index_close(indexRel, AccessShareLock);
heap_close(heapRel, NoLock);
MemoryContextSwitchTo(oldcontext);
FreeExecutorState(estate);
/* And we're done */
break;
}
}
return have_data;
}
| void get_join_variables | ( | PlannerInfo * | root, | |
| List * | args, | |||
| SpecialJoinInfo * | sjinfo, | |||
| VariableStatData * | vardata1, | |||
| VariableStatData * | vardata2, | |||
| bool * | join_is_reversed | |||
| ) |
Definition at line 4216 of file selfuncs.c.
References bms_is_subset(), elog, ERROR, examine_variable(), linitial, list_length(), lsecond, VariableStatData::rel, RelOptInfo::relids, SpecialJoinInfo::syn_lefthand, and SpecialJoinInfo::syn_righthand.
Referenced by eqjoinsel().
{
Node *left,
*right;
if (list_length(args) != 2)
elog(ERROR, "join operator should take two arguments");
left = (Node *) linitial(args);
right = (Node *) lsecond(args);
examine_variable(root, left, 0, vardata1);
examine_variable(root, right, 0, vardata2);
if (vardata1->rel &&
bms_is_subset(vardata1->rel->relids, sjinfo->syn_righthand))
*join_is_reversed = true; /* var1 is on RHS */
else if (vardata2->rel &&
bms_is_subset(vardata2->rel->relids, sjinfo->syn_lefthand))
*join_is_reversed = true; /* var2 is on LHS */
else
*join_is_reversed = false;
}
| bool get_restriction_variable | ( | PlannerInfo * | root, | |
| List * | args, | |||
| int | varRelid, | |||
| VariableStatData * | vardata, | |||
| Node ** | other, | |||
| bool * | varonleft | |||
| ) |
Definition at line 4156 of file selfuncs.c.
References estimate_expression_value(), examine_variable(), linitial, list_length(), lsecond, NULL, VariableStatData::rel, ReleaseVariableStats, and VariableStatData::var.
Referenced by arraycontsel(), eqsel(), ltreeparentsel(), patternsel(), rangesel(), scalargtsel(), scalarltsel(), and tsmatchsel().
{
Node *left,
*right;
VariableStatData rdata;
/* Fail if not a binary opclause (probably shouldn't happen) */
if (list_length(args) != 2)
return false;
left = (Node *) linitial(args);
right = (Node *) lsecond(args);
/*
* Examine both sides. Note that when varRelid is nonzero, Vars of other
* relations will be treated as pseudoconstants.
*/
examine_variable(root, left, varRelid, vardata);
examine_variable(root, right, varRelid, &rdata);
/*
* If one side is a variable and the other not, we win.
*/
if (vardata->rel && rdata.rel == NULL)
{
*varonleft = true;
*other = estimate_expression_value(root, rdata.var);
/* Assume we need no ReleaseVariableStats(rdata) here */
return true;
}
if (vardata->rel == NULL && rdata.rel)
{
*varonleft = false;
*other = estimate_expression_value(root, vardata->var);
/* Assume we need no ReleaseVariableStats(*vardata) here */
*vardata = rdata;
return true;
}
/* Ooops, clause has wrong structure (probably var op var) */
ReleaseVariableStats(*vardata);
ReleaseVariableStats(rdata);
return false;
}
| double get_variable_numdistinct | ( | VariableStatData * | vardata, | |
| bool * | isdefault | |||
| ) |
Definition at line 4613 of file selfuncs.c.
References BOOLOID, DEFAULT_NUM_DISTINCT, GETSTRUCT, HeapTupleIsValid, IsA, VariableStatData::isunique, NULL, ObjectIdAttributeNumber, VariableStatData::rel, SelfItemPointerAttributeNumber, VariableStatData::statsTuple, TableOidAttributeNumber, RelOptInfo::tuples, VariableStatData::var, and VariableStatData::vartype.
Referenced by add_unique_group_var(), eqjoinsel_inner(), eqjoinsel_semi(), estimate_hash_bucketsize(), var_eq_const(), and var_eq_non_const().
{
double stadistinct;
double ntuples;
*isdefault = false;
/*
* Determine the stadistinct value to use. There are cases where we can
* get an estimate even without a pg_statistic entry, or can get a better
* value than is in pg_statistic.
*/
if (HeapTupleIsValid(vardata->statsTuple))
{
/* Use the pg_statistic entry */
Form_pg_statistic stats;
stats = (Form_pg_statistic) GETSTRUCT(vardata->statsTuple);
stadistinct = stats->stadistinct;
}
else if (vardata->vartype == BOOLOID)
{
/*
* Special-case boolean columns: presumably, two distinct values.
*
* Are there any other datatypes we should wire in special estimates
* for?
*/
stadistinct = 2.0;
}
else
{
/*
* We don't keep statistics for system columns, but in some cases we
* can infer distinctness anyway.
*/
if (vardata->var && IsA(vardata->var, Var))
{
switch (((Var *) vardata->var)->varattno)
{
case ObjectIdAttributeNumber:
case SelfItemPointerAttributeNumber:
stadistinct = -1.0; /* unique */
break;
case TableOidAttributeNumber:
stadistinct = 1.0; /* only 1 value */
break;
default:
stadistinct = 0.0; /* means "unknown" */
break;
}
}
else
stadistinct = 0.0; /* means "unknown" */
/*
* XXX consider using estimate_num_groups on expressions?
*/
}
/*
* If there is a unique index or DISTINCT clause for the variable, assume
* it is unique no matter what pg_statistic says; the statistics could be
* out of date, or we might have found a partial unique index that proves
* the var is unique for this query.
*/
if (vardata->isunique)
stadistinct = -1.0;
/*
* If we had an absolute estimate, use that.
*/
if (stadistinct > 0.0)
return stadistinct;
/*
* Otherwise we need to get the relation size; punt if not available.
*/
if (vardata->rel == NULL)
{
*isdefault = true;
return DEFAULT_NUM_DISTINCT;
}
ntuples = vardata->rel->tuples;
if (ntuples <= 0.0)
{
*isdefault = true;
return DEFAULT_NUM_DISTINCT;
}
/*
* If we had a relative estimate, use that.
*/
if (stadistinct < 0.0)
return floor((-stadistinct * ntuples) + 0.5);
/*
* With no data, estimate ndistinct = ntuples if the table is small, else
* use default. We use DEFAULT_NUM_DISTINCT as the cutoff for "small" so
* that the behavior isn't discontinuous.
*/
if (ntuples < DEFAULT_NUM_DISTINCT)
return ntuples;
*isdefault = true;
return DEFAULT_NUM_DISTINCT;
}
| static bool get_variable_range | ( | PlannerInfo * | root, | |
| VariableStatData * | vardata, | |||
| Oid | sortop, | |||
| Datum * | min, | |||
| Datum * | max | |||
| ) | [static] |
Definition at line 4731 of file selfuncs.c.
References VariableStatData::atttype, VariableStatData::atttypmod, datumCopy(), DatumGetBool, DEFAULT_COLLATION_OID, fmgr_info(), free_attstatsslot(), FunctionCall2Coll(), get_actual_variable_range(), get_attstatsslot(), get_opcode(), get_typlenbyval(), HeapTupleIsValid, i, InvalidOid, NULL, STATISTIC_KIND_HISTOGRAM, STATISTIC_KIND_MCV, VariableStatData::statsTuple, and values.
Referenced by mergejoinscansel().
{
Datum tmin = 0;
Datum tmax = 0;
bool have_data = false;
int16 typLen;
bool typByVal;
Datum *values;
int nvalues;
int i;
/*
* XXX It's very tempting to try to use the actual column min and max, if
* we can get them relatively-cheaply with an index probe. However, since
* this function is called many times during join planning, that could
* have unpleasant effects on planning speed. Need more investigation
* before enabling this.
*/
#ifdef NOT_USED
if (get_actual_variable_range(root, vardata, sortop, min, max))
return true;
#endif
if (!HeapTupleIsValid(vardata->statsTuple))
{
/* no stats available, so default result */
return false;
}
get_typlenbyval(vardata->atttype, &typLen, &typByVal);
/*
* If there is a histogram, grab the first and last values.
*
* If there is a histogram that is sorted with some other operator than
* the one we want, fail --- this suggests that there is data we can't
* use.
*/
if (get_attstatsslot(vardata->statsTuple,
vardata->atttype, vardata->atttypmod,
STATISTIC_KIND_HISTOGRAM, sortop,
NULL,
&values, &nvalues,
NULL, NULL))
{
if (nvalues > 0)
{
tmin = datumCopy(values[0], typByVal, typLen);
tmax = datumCopy(values[nvalues - 1], typByVal, typLen);
have_data = true;
}
free_attstatsslot(vardata->atttype, values, nvalues, NULL, 0);
}
else if (get_attstatsslot(vardata->statsTuple,
vardata->atttype, vardata->atttypmod,
STATISTIC_KIND_HISTOGRAM, InvalidOid,
NULL,
&values, &nvalues,
NULL, NULL))
{
free_attstatsslot(vardata->atttype, values, nvalues, NULL, 0);
return false;
}
/*
* If we have most-common-values info, look for extreme MCVs. This is
* needed even if we also have a histogram, since the histogram excludes
* the MCVs. However, usually the MCVs will not be the extreme values, so
* avoid unnecessary data copying.
*/
if (get_attstatsslot(vardata->statsTuple,
vardata->atttype, vardata->atttypmod,
STATISTIC_KIND_MCV, InvalidOid,
NULL,
&values, &nvalues,
NULL, NULL))
{
bool tmin_is_mcv = false;
bool tmax_is_mcv = false;
FmgrInfo opproc;
fmgr_info(get_opcode(sortop), &opproc);
for (i = 0; i < nvalues; i++)
{
if (!have_data)
{
tmin = tmax = values[i];
tmin_is_mcv = tmax_is_mcv = have_data = true;
continue;
}
if (DatumGetBool(FunctionCall2Coll(&opproc,
DEFAULT_COLLATION_OID,
values[i], tmin)))
{
tmin = values[i];
tmin_is_mcv = true;
}
if (DatumGetBool(FunctionCall2Coll(&opproc,
DEFAULT_COLLATION_OID,
tmax, values[i])))
{
tmax = values[i];
tmax_is_mcv = true;
}
}
if (tmin_is_mcv)
tmin = datumCopy(tmin, typByVal, typLen);
if (tmax_is_mcv)
tmax = datumCopy(tmax, typByVal, typLen);
free_attstatsslot(vardata->atttype, values, nvalues, NULL, 0);
}
*min = tmin;
*max = tmax;
return have_data;
}
| static bool gincost_opexpr | ( | IndexOptInfo * | index, | |
| OpExpr * | clause, | |||
| GinQualCounts * | counts | |||
| ) | [static] |
Definition at line 6846 of file selfuncs.c.
References arg, elog, ERROR, GinQualCounts::exactEntries, find_index_column(), get_commutator(), get_leftop(), get_rightop(), gincost_pattern(), IsA, and GinQualCounts::searchEntries.
Referenced by gincostestimate().
{
Node *leftop = get_leftop((Expr *) clause);
Node *rightop = get_rightop((Expr *) clause);
Oid clause_op = clause->opno;
int indexcol;
Node *operand;
/* Locate the operand being compared to the index column */
if ((indexcol = find_index_column(leftop, index)) >= 0)
{
operand = rightop;
}
else if ((indexcol = find_index_column(rightop, index)) >= 0)
{
operand = leftop;
clause_op = get_commutator(clause_op);
}
else
{
elog(ERROR, "could not match index to operand");
operand = NULL; /* keep compiler quiet */
}
if (IsA(operand, RelabelType))
operand = (Node *) ((RelabelType *) operand)->arg;
/*
* It's impossible to call extractQuery method for unknown operand. So
* unless operand is a Const we can't do much; just assume there will be
* one ordinary search entry from the operand at runtime.
*/
if (!IsA(operand, Const))
{
counts->exactEntries++;
counts->searchEntries++;
return true;
}
/* If Const is null, there can be no matches */
if (((Const *) operand)->constisnull)
return false;
/* Otherwise, apply extractQuery and get the actual term counts */
return gincost_pattern(index, indexcol, clause_op,
((Const *) operand)->constvalue,
counts);
}
| static bool gincost_pattern | ( | IndexOptInfo * | index, | |
| int | indexcol, | |||
| Oid | clause_op, | |||
| Datum | query, | |||
| GinQualCounts * | counts | |||
| ) | [static] |
Definition at line 6744 of file selfuncs.c.
References elog, ERROR, GinQualCounts::exactEntries, get_op_opfamily_properties(), get_opfamily_proc(), get_rel_name(), GIN_EXTRACTQUERY_PROC, GIN_SEARCH_MODE_DEFAULT, GIN_SEARCH_MODE_INCLUDE_EMPTY, GinQualCounts::haveFullScan, i, IndexOptInfo::indexcollations, IndexOptInfo::indexoid, OidFunctionCall7Coll(), OidIsValid, IndexOptInfo::opcintype, IndexOptInfo::opfamily, GinQualCounts::partialEntries, PointerGetDatum, GinQualCounts::searchEntries, and UInt16GetDatum.
Referenced by gincost_opexpr(), and gincost_scalararrayopexpr().
{
Oid extractProcOid;
Oid collation;
int strategy_op;
Oid lefttype,
righttype;
int32 nentries = 0;
bool *partial_matches = NULL;
Pointer *extra_data = NULL;
bool *nullFlags = NULL;
int32 searchMode = GIN_SEARCH_MODE_DEFAULT;
int32 i;
/*
* Get the operator's strategy number and declared input data types within
* the index opfamily. (We don't need the latter, but we use
* get_op_opfamily_properties because it will throw error if it fails to
* find a matching pg_amop entry.)
*/
get_op_opfamily_properties(clause_op, index->opfamily[indexcol], false,
&strategy_op, &lefttype, &righttype);
/*
* GIN always uses the "default" support functions, which are those with
* lefttype == righttype == the opclass' opcintype (see
* IndexSupportInitialize in relcache.c).
*/
extractProcOid = get_opfamily_proc(index->opfamily[indexcol],
index->opcintype[indexcol],
index->opcintype[indexcol],
GIN_EXTRACTQUERY_PROC);
if (!OidIsValid(extractProcOid))
{
/* should not happen; throw same error as index_getprocinfo */
elog(ERROR, "missing support function %d for attribute %d of index \"%s\"",
GIN_EXTRACTQUERY_PROC, indexcol + 1,
get_rel_name(index->indexoid));
}
/*
* Choose collation to pass to extractProc (should match initGinState).
*/
if (OidIsValid(index->indexcollations[indexcol]))
collation = index->indexcollations[indexcol];
else
collation = DEFAULT_COLLATION_OID;
OidFunctionCall7Coll(extractProcOid,
collation,
query,
PointerGetDatum(&nentries),
UInt16GetDatum(strategy_op),
PointerGetDatum(&partial_matches),
PointerGetDatum(&extra_data),
PointerGetDatum(&nullFlags),
PointerGetDatum(&searchMode));
if (nentries <= 0 && searchMode == GIN_SEARCH_MODE_DEFAULT)
{
/* No match is possible */
return false;
}
for (i = 0; i < nentries; i++)
{
/*
* For partial match we haven't any information to estimate number of
* matched entries in index, so, we just estimate it as 100
*/
if (partial_matches && partial_matches[i])
counts->partialEntries += 100;
else
counts->exactEntries++;
counts->searchEntries++;
}
if (searchMode == GIN_SEARCH_MODE_INCLUDE_EMPTY)
{
/* Treat "include empty" like an exact-match item */
counts->exactEntries++;
counts->searchEntries++;
}
else if (searchMode != GIN_SEARCH_MODE_DEFAULT)
{
/* It's GIN_SEARCH_MODE_ALL */
counts->haveFullScan = true;
}
return true;
}
| static bool gincost_scalararrayopexpr | ( | IndexOptInfo * | index, | |
| ScalarArrayOpExpr * | clause, | |||
| double | numIndexEntries, | |||
| GinQualCounts * | counts | |||
| ) | [static] |
Definition at line 6908 of file selfuncs.c.
References arg, ScalarArrayOpExpr::args, ARR_ELEMTYPE, GinQualCounts::arrayScans, Assert, DatumGetArrayTypeP, deconstruct_array(), elog, ERROR, estimate_array_length(), GinQualCounts::exactEntries, find_index_column(), get_typlenbyvalalign(), gincost_pattern(), GinQualCounts::haveFullScan, i, IsA, linitial, lsecond, ScalarArrayOpExpr::opno, GinQualCounts::partialEntries, GinQualCounts::searchEntries, and ScalarArrayOpExpr::useOr.
Referenced by gincostestimate().
{
Node *leftop = (Node *) linitial(clause->args);
Node *rightop = (Node *) lsecond(clause->args);
Oid clause_op = clause->opno;
int indexcol;
ArrayType *arrayval;
int16 elmlen;
bool elmbyval;
char elmalign;
int numElems;
Datum *elemValues;
bool *elemNulls;
GinQualCounts arraycounts;
int numPossible = 0;
int i;
Assert(clause->useOr);
/* index column must be on the left */
if ((indexcol = find_index_column(leftop, index)) < 0)
elog(ERROR, "could not match index to operand");
if (IsA(rightop, RelabelType))
rightop = (Node *) ((RelabelType *) rightop)->arg;
/*
* It's impossible to call extractQuery method for unknown operand. So
* unless operand is a Const we can't do much; just assume there will be
* one ordinary search entry from each array entry at runtime, and fall
* back on a probably-bad estimate of the number of array entries.
*/
if (!IsA(rightop, Const))
{
counts->exactEntries++;
counts->searchEntries++;
counts->arrayScans *= estimate_array_length(rightop);
return true;
}
/* If Const is null, there can be no matches */
if (((Const *) rightop)->constisnull)
return false;
/* Otherwise, extract the array elements and iterate over them */
arrayval = DatumGetArrayTypeP(((Const *) rightop)->constvalue);
get_typlenbyvalalign(ARR_ELEMTYPE(arrayval),
&elmlen, &elmbyval, &elmalign);
deconstruct_array(arrayval,
ARR_ELEMTYPE(arrayval),
elmlen, elmbyval, elmalign,
&elemValues, &elemNulls, &numElems);
memset(&arraycounts, 0, sizeof(arraycounts));
for (i = 0; i < numElems; i++)
{
GinQualCounts elemcounts;
/* NULL can't match anything, so ignore, as the executor will */
if (elemNulls[i])
continue;
/* Otherwise, apply extractQuery and get the actual term counts */
memset(&elemcounts, 0, sizeof(elemcounts));
if (gincost_pattern(index, indexcol, clause_op, elemValues[i],
&elemcounts))
{
/* We ignore array elements that are unsatisfiable patterns */
numPossible++;
if (elemcounts.haveFullScan)
{
/*
* Full index scan will be required. We treat this as if
* every key in the index had been listed in the query; is
* that reasonable?
*/
elemcounts.partialEntries = 0;
elemcounts.exactEntries = numIndexEntries;
elemcounts.searchEntries = numIndexEntries;
}
arraycounts.partialEntries += elemcounts.partialEntries;
arraycounts.exactEntries += elemcounts.exactEntries;
arraycounts.searchEntries += elemcounts.searchEntries;
}
}
if (numPossible == 0)
{
/* No satisfiable patterns in the array */
return false;
}
/*
* Now add the averages to the global counts. This will give us an
* estimate of the average number of terms searched for in each indexscan,
* including contributions from both array and non-array quals.
*/
counts->partialEntries += arraycounts.partialEntries / numPossible;
counts->exactEntries += arraycounts.exactEntries / numPossible;
counts->searchEntries += arraycounts.searchEntries / numPossible;
counts->arrayScans *= numPossible;
return true;
}
| Datum gincostestimate | ( | PG_FUNCTION_ARGS | ) |
Definition at line 7023 of file selfuncs.c.
References AccessShareLock, GinQualCounts::arrayScans, Assert, RestrictInfo::clause, clauselist_selectivity(), cost_qual_eval(), cpu_index_tuple_cost, cpu_operator_cost, elog, ERROR, GinQualCounts::exactEntries, get_tablespace_page_costs(), gincost_opexpr(), gincost_scalararrayopexpr(), ginGetStats(), GinQualCounts::haveFullScan, index_close(), index_open(), index_pages_fetched(), IndexPath::indexinfo, IndexOptInfo::indexoid, IndexPath::indexorderbys, IndexPath::indexquals, IndexOptInfo::indpred, IsA, JOIN_INNER, lfirst, list_concat(), list_length(), list_make1, Min, GinStatsData::nDataPages, GinStatsData::nEntries, GinStatsData::nEntryPages, NIL, nodeTag, GinStatsData::nPendingPages, GinStatsData::nTotalPages, NULL, IndexOptInfo::pages, GinQualCounts::partialEntries, QualCost::per_tuple, PG_GETARG_FLOAT8, PG_GETARG_POINTER, PG_RETURN_VOID, predicate_implied_by(), IndexOptInfo::rel, RelOptInfo::relid, IndexOptInfo::reltablespace, rint(), scale, GinQualCounts::searchEntries, SizeOfIptrData, QualCost::startup, and IndexOptInfo::tuples.
{
PlannerInfo *root = (PlannerInfo *) PG_GETARG_POINTER(0);
IndexPath *path = (IndexPath *) PG_GETARG_POINTER(1);
double loop_count = PG_GETARG_FLOAT8(2);
Cost *indexStartupCost = (Cost *) PG_GETARG_POINTER(3);
Cost *indexTotalCost = (Cost *) PG_GETARG_POINTER(4);
Selectivity *indexSelectivity = (Selectivity *) PG_GETARG_POINTER(5);
double *indexCorrelation = (double *) PG_GETARG_POINTER(6);
IndexOptInfo *index = path->indexinfo;
List *indexQuals = path->indexquals;
List *indexOrderBys = path->indexorderbys;
ListCell *l;
List *selectivityQuals;
double numPages = index->pages,
numTuples = index->tuples;
double numEntryPages,
numDataPages,
numPendingPages,
numEntries;
GinQualCounts counts;
bool matchPossible;
double entryPagesFetched,
dataPagesFetched,
dataPagesFetchedBySel;
double qual_op_cost,
qual_arg_cost,
spc_random_page_cost,
outer_scans;
QualCost index_qual_cost;
Relation indexRel;
GinStatsData ginStats;
/*
* Obtain statistic information from the meta page
*/
indexRel = index_open(index->indexoid, AccessShareLock);
ginGetStats(indexRel, &ginStats);
index_close(indexRel, AccessShareLock);
numEntryPages = ginStats.nEntryPages;
numDataPages = ginStats.nDataPages;
numPendingPages = ginStats.nPendingPages;
numEntries = ginStats.nEntries;
/*
* nPendingPages can be trusted, but the other fields are as of the last
* VACUUM. Scale them by the ratio numPages / nTotalPages to account for
* growth since then. If the fields are zero (implying no VACUUM at all,
* and an index created pre-9.1), assume all pages are entry pages.
*/
if (ginStats.nTotalPages == 0 || ginStats.nEntryPages == 0)
{
numEntryPages = numPages;
numDataPages = 0;
numEntries = numTuples; /* bogus, but no other info available */
}
else
{
double scale = numPages / ginStats.nTotalPages;
numEntryPages = ceil(numEntryPages * scale);
numDataPages = ceil(numDataPages * scale);
numEntries = ceil(numEntries * scale);
/* ensure we didn't round up too much */
numEntryPages = Min(numEntryPages, numPages);
numDataPages = Min(numDataPages, numPages - numEntryPages);
}
/* In an empty index, numEntries could be zero. Avoid divide-by-zero */
if (numEntries < 1)
numEntries = 1;
/*
* Include predicate in selectivityQuals (should match
* genericcostestimate)
*/
if (index->indpred != NIL)
{
List *predExtraQuals = NIL;
foreach(l, index->indpred)
{
Node *predQual = (Node *) lfirst(l);
List *oneQual = list_make1(predQual);
if (!predicate_implied_by(oneQual, indexQuals))
predExtraQuals = list_concat(predExtraQuals, oneQual);
}
/* list_concat avoids modifying the passed-in indexQuals list */
selectivityQuals = list_concat(predExtraQuals, indexQuals);
}
else
selectivityQuals = indexQuals;
/* Estimate the fraction of main-table tuples that will be visited */
*indexSelectivity = clauselist_selectivity(root, selectivityQuals,
index->rel->relid,
JOIN_INNER,
NULL);
/* fetch estimated page cost for schema containing index */
get_tablespace_page_costs(index->reltablespace,
&spc_random_page_cost,
NULL);
/*
* Generic assumption about index correlation: there isn't any.
*/
*indexCorrelation = 0.0;
/*
* Examine quals to estimate number of search entries & partial matches
*/
memset(&counts, 0, sizeof(counts));
counts.arrayScans = 1;
matchPossible = true;
foreach(l, indexQuals)
{
RestrictInfo *rinfo = (RestrictInfo *) lfirst(l);
Expr *clause;
Assert(IsA(rinfo, RestrictInfo));
clause = rinfo->clause;
if (IsA(clause, OpExpr))
{
matchPossible = gincost_opexpr(index,
(OpExpr *) clause,
&counts);
if (!matchPossible)
break;
}
else if (IsA(clause, ScalarArrayOpExpr))
{
matchPossible = gincost_scalararrayopexpr(index,
(ScalarArrayOpExpr *) clause,
numEntries,
&counts);
if (!matchPossible)
break;
}
else
{
/* shouldn't be anything else for a GIN index */
elog(ERROR, "unsupported GIN indexqual type: %d",
(int) nodeTag(clause));
}
}
/* Fall out if there were any provably-unsatisfiable quals */
if (!matchPossible)
{
*indexStartupCost = 0;
*indexTotalCost = 0;
*indexSelectivity = 0;
PG_RETURN_VOID();
}
if (counts.haveFullScan || indexQuals == NIL)
{
/*
* Full index scan will be required. We treat this as if every key in
* the index had been listed in the query; is that reasonable?
*/
counts.partialEntries = 0;
counts.exactEntries = numEntries;
counts.searchEntries = numEntries;
}
/* Will we have more than one iteration of a nestloop scan? */
outer_scans = loop_count;
/*
* Compute cost to begin scan, first of all, pay attention to pending
* list.
*/
entryPagesFetched = numPendingPages;
/*
* Estimate number of entry pages read. We need to do
* counts.searchEntries searches. Use a power function as it should be,
* but tuples on leaf pages usually is much greater. Here we include all
* searches in entry tree, including search of first entry in partial
* match algorithm
*/
entryPagesFetched += ceil(counts.searchEntries * rint(pow(numEntryPages, 0.15)));
/*
* Add an estimate of entry pages read by partial match algorithm. It's a
* scan over leaf pages in entry tree. We haven't any useful stats here,
* so estimate it as proportion.
*/
entryPagesFetched += ceil(numEntryPages * counts.partialEntries / numEntries);
/*
* Partial match algorithm reads all data pages before doing actual scan,
* so it's a startup cost. Again, we haven't any useful stats here, so,
* estimate it as proportion
*/
dataPagesFetched = ceil(numDataPages * counts.partialEntries / numEntries);
/*
* Calculate cache effects if more than one scan due to nestloops or array
* quals. The result is pro-rated per nestloop scan, but the array qual
* factor shouldn't be pro-rated (compare genericcostestimate).
*/
if (outer_scans > 1 || counts.arrayScans > 1)
{
entryPagesFetched *= outer_scans * counts.arrayScans;
entryPagesFetched = index_pages_fetched(entryPagesFetched,
(BlockNumber) numEntryPages,
numEntryPages, root);
entryPagesFetched /= outer_scans;
dataPagesFetched *= outer_scans * counts.arrayScans;
dataPagesFetched = index_pages_fetched(dataPagesFetched,
(BlockNumber) numDataPages,
numDataPages, root);
dataPagesFetched /= outer_scans;
}
/*
* Here we use random page cost because logically-close pages could be far
* apart on disk.
*/
*indexStartupCost = (entryPagesFetched + dataPagesFetched) * spc_random_page_cost;
/*
* Now we compute the number of data pages fetched while the scan
* proceeds.
*/
/* data pages scanned for each exact (non-partial) matched entry */
dataPagesFetched = ceil(numDataPages * counts.exactEntries / numEntries);
/*
* Estimate number of data pages read, using selectivity estimation and
* capacity of data page.
*/
dataPagesFetchedBySel = ceil(*indexSelectivity *
(numTuples / (BLCKSZ / SizeOfIptrData)));
if (dataPagesFetchedBySel > dataPagesFetched)
{
/*
* At least one of entries is very frequent and, unfortunately, we
* couldn't get statistic about entries (only tsvector has such
* statistics). So, we obviously have too small estimation of pages
* fetched from data tree. Re-estimate it from known capacity of data
* pages
*/
dataPagesFetched = dataPagesFetchedBySel;
}
/* Account for cache effects, the same as above */
if (outer_scans > 1 || counts.arrayScans > 1)
{
dataPagesFetched *= outer_scans * counts.arrayScans;
dataPagesFetched = index_pages_fetched(dataPagesFetched,
(BlockNumber) numDataPages,
numDataPages, root);
dataPagesFetched /= outer_scans;
}
/* And apply random_page_cost as the cost per page */
*indexTotalCost = *indexStartupCost +
dataPagesFetched * spc_random_page_cost;
/*
* Add on index qual eval costs, much as in genericcostestimate
*/
cost_qual_eval(&index_qual_cost, indexQuals, root);
qual_arg_cost = index_qual_cost.startup + index_qual_cost.per_tuple;
cost_qual_eval(&index_qual_cost, indexOrderBys, root);
qual_arg_cost += index_qual_cost.startup + index_qual_cost.per_tuple;
qual_op_cost = cpu_operator_cost *
(list_length(indexQuals) + list_length(indexOrderBys));
qual_arg_cost -= qual_op_cost;
if (qual_arg_cost < 0) /* just in case... */
qual_arg_cost = 0;
*indexStartupCost += qual_arg_cost;
*indexTotalCost += qual_arg_cost;
*indexTotalCost += (numTuples * *indexSelectivity) * (cpu_index_tuple_cost + qual_op_cost);
PG_RETURN_VOID();
}
| Datum gistcostestimate | ( | PG_FUNCTION_ARGS | ) |
Definition at line 6586 of file selfuncs.c.
References cpu_operator_cost, genericcostestimate(), GenericCosts::indexCorrelation, IndexPath::indexinfo, GenericCosts::indexSelectivity, GenericCosts::indexStartupCost, GenericCosts::indexTotalCost, MemSet, GenericCosts::num_sa_scans, IndexOptInfo::pages, PG_GETARG_FLOAT8, PG_GETARG_POINTER, PG_RETURN_VOID, IndexOptInfo::tree_height, and IndexOptInfo::tuples.
{
PlannerInfo *root = (PlannerInfo *) PG_GETARG_POINTER(0);
IndexPath *path = (IndexPath *) PG_GETARG_POINTER(1);
double loop_count = PG_GETARG_FLOAT8(2);
Cost *indexStartupCost = (Cost *) PG_GETARG_POINTER(3);
Cost *indexTotalCost = (Cost *) PG_GETARG_POINTER(4);
Selectivity *indexSelectivity = (Selectivity *) PG_GETARG_POINTER(5);
double *indexCorrelation = (double *) PG_GETARG_POINTER(6);
IndexOptInfo *index = path->indexinfo;
GenericCosts costs;
Cost descentCost;
MemSet(&costs, 0, sizeof(costs));
genericcostestimate(root, path, loop_count, &costs);
/*
* We model index descent costs similarly to those for btree, but to do
* that we first need an idea of the tree height. We somewhat arbitrarily
* assume that the fanout is 100, meaning the tree height is at most
* log100(index->pages).
*
* Although this computation isn't really expensive enough to require
* caching, we might as well use index->tree_height to cache it.
*/
if (index->tree_height < 0) /* unknown? */
{
if (index->pages > 1) /* avoid computing log(0) */
index->tree_height = (int) (log(index->pages) / log(100.0));
else
index->tree_height = 0;
}
/*
* Add a CPU-cost component to represent the costs of initial descent.
* We just use log(N) here not log2(N) since the branching factor isn't
* necessarily two anyway. As for btree, charge once per SA scan.
*/
if (index->tuples > 1) /* avoid computing log(0) */
{
descentCost = ceil(log(index->tuples)) * cpu_operator_cost;
costs.indexStartupCost += descentCost;
costs.indexTotalCost += costs.num_sa_scans * descentCost;
}
/*
* Likewise add a per-page charge, calculated the same as for btrees.
*/
descentCost = (index->tree_height + 1) * 50.0 * cpu_operator_cost;
costs.indexStartupCost += descentCost;
costs.indexTotalCost += costs.num_sa_scans * descentCost;
*indexStartupCost = costs.indexStartupCost;
*indexTotalCost = costs.indexTotalCost;
*indexSelectivity = costs.indexSelectivity;
*indexCorrelation = costs.indexCorrelation;
PG_RETURN_VOID();
}
| Datum hashcostestimate | ( | PG_FUNCTION_ARGS | ) |
Definition at line 6537 of file selfuncs.c.
References genericcostestimate(), GenericCosts::indexCorrelation, GenericCosts::indexSelectivity, GenericCosts::indexStartupCost, GenericCosts::indexTotalCost, MemSet, PG_GETARG_FLOAT8, PG_GETARG_POINTER, and PG_RETURN_VOID.
{
PlannerInfo *root = (PlannerInfo *) PG_GETARG_POINTER(0);
IndexPath *path = (IndexPath *) PG_GETARG_POINTER(1);
double loop_count = PG_GETARG_FLOAT8(2);
Cost *indexStartupCost = (Cost *) PG_GETARG_POINTER(3);
Cost *indexTotalCost = (Cost *) PG_GETARG_POINTER(4);
Selectivity *indexSelectivity = (Selectivity *) PG_GETARG_POINTER(5);
double *indexCorrelation = (double *) PG_GETARG_POINTER(6);
GenericCosts costs;
MemSet(&costs, 0, sizeof(costs));
genericcostestimate(root, path, loop_count, &costs);
/*
* A hash index has no descent costs as such, since the index AM can go
* directly to the target bucket after computing the hash value. There
* are a couple of other hash-specific costs that we could conceivably add
* here, though:
*
* Ideally we'd charge spc_random_page_cost for each page in the target
* bucket, not just the numIndexPages pages that genericcostestimate
* thought we'd visit. However in most cases we don't know which bucket
* that will be. There's no point in considering the average bucket size
* because the hash AM makes sure that's always one page.
*
* Likewise, we could consider charging some CPU for each index tuple in
* the bucket, if we knew how many there were. But the per-tuple cost is
* just a hash value comparison, not a general datatype-dependent
* comparison, so any such charge ought to be quite a bit less than
* cpu_operator_cost; which makes it probably not worth worrying about.
*
* A bigger issue is that chance hash-value collisions will result in
* wasted probes into the heap. We don't currently attempt to model this
* cost on the grounds that it's rare, but maybe it's not rare enough.
* (Any fix for this ought to consider the generic lossy-operator problem,
* though; it's not entirely hash-specific.)
*/
*indexStartupCost = costs.indexStartupCost;
*indexTotalCost = costs.indexTotalCost;
*indexSelectivity = costs.indexSelectivity;
*indexCorrelation = costs.indexCorrelation;
PG_RETURN_VOID();
}
| double histogram_selectivity | ( | VariableStatData * | vardata, | |
| FmgrInfo * | opproc, | |||
| Datum | constval, | |||
| bool | varonleft, | |||
| int | min_hist_size, | |||
| int | n_skip, | |||
| int * | hist_size | |||
| ) |
Definition at line 680 of file selfuncs.c.
References Assert, VariableStatData::atttype, VariableStatData::atttypmod, DatumGetBool, DEFAULT_COLLATION_OID, free_attstatsslot(), FunctionCall2Coll(), get_attstatsslot(), HeapTupleIsValid, i, InvalidOid, NULL, STATISTIC_KIND_HISTOGRAM, VariableStatData::statsTuple, and values.
Referenced by ltreeparentsel(), and patternsel().
{
double result;
Datum *values;
int nvalues;
/* check sanity of parameters */
Assert(n_skip >= 0);
Assert(min_hist_size > 2 * n_skip);
if (HeapTupleIsValid(vardata->statsTuple) &&
get_attstatsslot(vardata->statsTuple,
vardata->atttype, vardata->atttypmod,
STATISTIC_KIND_HISTOGRAM, InvalidOid,
NULL,
&values, &nvalues,
NULL, NULL))
{
*hist_size = nvalues;
if (nvalues >= min_hist_size)
{
int nmatch = 0;
int i;
for (i = n_skip; i < nvalues - n_skip; i++)
{
if (varonleft ?
DatumGetBool(FunctionCall2Coll(opproc,
DEFAULT_COLLATION_OID,
values[i],
constval)) :
DatumGetBool(FunctionCall2Coll(opproc,
DEFAULT_COLLATION_OID,
constval,
values[i])))
nmatch++;
}
result = ((double) nmatch) / ((double) (nvalues - 2 * n_skip));
}
else
result = -1;
free_attstatsslot(vardata->atttype, values, nvalues, NULL, 0);
}
else
{
*hist_size = 0;
result = -1;
}
return result;
}
| Datum iclikejoinsel | ( | PG_FUNCTION_ARGS | ) |
Definition at line 2721 of file selfuncs.c.
References Pattern_Type_Like_IC, patternjoinsel(), and PG_RETURN_FLOAT8.
{
PG_RETURN_FLOAT8(patternjoinsel(fcinfo, Pattern_Type_Like_IC, false));
}
| Datum iclikesel | ( | PG_FUNCTION_ARGS | ) |
Definition at line 1401 of file selfuncs.c.
References Pattern_Type_Like_IC, patternsel(), and PG_RETURN_FLOAT8.
{
PG_RETURN_FLOAT8(patternsel(fcinfo, Pattern_Type_Like_IC, false));
}
| Datum icnlikejoinsel | ( | PG_FUNCTION_ARGS | ) |
Definition at line 2757 of file selfuncs.c.
References Pattern_Type_Like_IC, patternjoinsel(), and PG_RETURN_FLOAT8.
{
PG_RETURN_FLOAT8(patternjoinsel(fcinfo, Pattern_Type_Like_IC, true));
}
| Datum icnlikesel | ( | PG_FUNCTION_ARGS | ) |
Definition at line 1437 of file selfuncs.c.
References Pattern_Type_Like_IC, patternsel(), and PG_RETURN_FLOAT8.
{
PG_RETURN_FLOAT8(patternsel(fcinfo, Pattern_Type_Like_IC, true));
}
| Datum icregexeqjoinsel | ( | PG_FUNCTION_ARGS | ) |
Definition at line 2703 of file selfuncs.c.
References Pattern_Type_Regex_IC, patternjoinsel(), and PG_RETURN_FLOAT8.
{
PG_RETURN_FLOAT8(patternjoinsel(fcinfo, Pattern_Type_Regex_IC, false));
}
| Datum icregexeqsel | ( | PG_FUNCTION_ARGS | ) |
Definition at line 1383 of file selfuncs.c.
References Pattern_Type_Regex_IC, patternsel(), and PG_RETURN_FLOAT8.
{
PG_RETURN_FLOAT8(patternsel(fcinfo, Pattern_Type_Regex_IC, false));
}
| Datum icregexnejoinsel | ( | PG_FUNCTION_ARGS | ) |
Definition at line 2739 of file selfuncs.c.
References Pattern_Type_Regex_IC, patternjoinsel(), and PG_RETURN_FLOAT8.
{
PG_RETURN_FLOAT8(patternjoinsel(fcinfo, Pattern_Type_Regex_IC, true));
}
| Datum icregexnesel | ( | PG_FUNCTION_ARGS | ) |
Definition at line 1419 of file selfuncs.c.
References Pattern_Type_Regex_IC, patternsel(), and PG_RETURN_FLOAT8.
{
PG_RETURN_FLOAT8(patternsel(fcinfo, Pattern_Type_Regex_IC, true));
}
| static double ineq_histogram_selectivity | ( | PlannerInfo * | root, | |
| VariableStatData * | vardata, | |||
| FmgrInfo * | opproc, | |||
| bool | isgt, | |||
| Datum | constval, | |||
| Oid | consttype | |||
| ) | [static] |
Definition at line 748 of file selfuncs.c.
References VariableStatData::atttype, VariableStatData::atttypmod, CLAMP_PROBABILITY, convert_to_scalar(), DatumGetBool, DEFAULT_COLLATION_OID, free_attstatsslot(), FunctionCall2Coll(), get_actual_variable_range(), get_attstatsslot(), HeapTupleIsValid, i, InvalidOid, NULL, STATISTIC_KIND_HISTOGRAM, VariableStatData::statsTuple, val, values, and VariableStatData::vartype.
Referenced by prefix_selectivity(), and scalarineqsel().
{
double hist_selec;
Oid hist_op;
Datum *values;
int nvalues;
hist_selec = -1.0;
/*
* Someday, ANALYZE might store more than one histogram per rel/att,
* corresponding to more than one possible sort ordering defined for the
* column type. However, to make that work we will need to figure out
* which staop to search for --- it's not necessarily the one we have at
* hand! (For example, we might have a '<=' operator rather than the '<'
* operator that will appear in staop.) For now, assume that whatever
* appears in pg_statistic is sorted the same way our operator sorts, or
* the reverse way if isgt is TRUE.
*/
if (HeapTupleIsValid(vardata->statsTuple) &&
get_attstatsslot(vardata->statsTuple,
vardata->atttype, vardata->atttypmod,
STATISTIC_KIND_HISTOGRAM, InvalidOid,
&hist_op,
&values, &nvalues,
NULL, NULL))
{
if (nvalues > 1)
{
/*
* Use binary search to find proper location, ie, the first slot
* at which the comparison fails. (If the given operator isn't
* actually sort-compatible with the histogram, you'll get garbage
* results ... but probably not any more garbage-y than you would
* from the old linear search.)
*
* If the binary search accesses the first or last histogram
* entry, we try to replace that endpoint with the true column min
* or max as found by get_actual_variable_range(). This
* ameliorates misestimates when the min or max is moving as a
* result of changes since the last ANALYZE. Note that this could
* result in effectively including MCVs into the histogram that
* weren't there before, but we don't try to correct for that.
*/
double histfrac;
int lobound = 0; /* first possible slot to search */
int hibound = nvalues; /* last+1 slot to search */
bool have_end = false;
/*
* If there are only two histogram entries, we'll want up-to-date
* values for both. (If there are more than two, we need at most
* one of them to be updated, so we deal with that within the
* loop.)
*/
if (nvalues == 2)
have_end = get_actual_variable_range(root,
vardata,
hist_op,
&values[0],
&values[1]);
while (lobound < hibound)
{
int probe = (lobound + hibound) / 2;
bool ltcmp;
/*
* If we find ourselves about to compare to the first or last
* histogram entry, first try to replace it with the actual
* current min or max (unless we already did so above).
*/
if (probe == 0 && nvalues > 2)
have_end = get_actual_variable_range(root,
vardata,
hist_op,
&values[0],
NULL);
else if (probe == nvalues - 1 && nvalues > 2)
have_end = get_actual_variable_range(root,
vardata,
hist_op,
NULL,
&values[probe]);
ltcmp = DatumGetBool(FunctionCall2Coll(opproc,
DEFAULT_COLLATION_OID,
values[probe],
constval));
if (isgt)
ltcmp = !ltcmp;
if (ltcmp)
lobound = probe + 1;
else
hibound = probe;
}
if (lobound <= 0)
{
/* Constant is below lower histogram boundary. */
histfrac = 0.0;
}
else if (lobound >= nvalues)
{
/* Constant is above upper histogram boundary. */
histfrac = 1.0;
}
else
{
int i = lobound;
double val,
high,
low;
double binfrac;
/*
* We have values[i-1] <= constant <= values[i].
*
* Convert the constant and the two nearest bin boundary
* values to a uniform comparison scale, and do a linear
* interpolation within this bin.
*/
if (convert_to_scalar(constval, consttype, &val,
values[i - 1], values[i],
vardata->vartype,
&low, &high))
{
if (high <= low)
{
/* cope if bin boundaries appear identical */
binfrac = 0.5;
}
else if (val <= low)
binfrac = 0.0;
else if (val >= high)
binfrac = 1.0;
else
{
binfrac = (val - low) / (high - low);
/*
* Watch out for the possibility that we got a NaN or
* Infinity from the division. This can happen
* despite the previous checks, if for example "low"
* is -Infinity.
*/
if (isnan(binfrac) ||
binfrac < 0.0 || binfrac > 1.0)
binfrac = 0.5;
}
}
else
{
/*
* Ideally we'd produce an error here, on the grounds that
* the given operator shouldn't have scalarXXsel
* registered as its selectivity func unless we can deal
* with its operand types. But currently, all manner of
* stuff is invoking scalarXXsel, so give a default
* estimate until that can be fixed.
*/
binfrac = 0.5;
}
/*
* Now, compute the overall selectivity across the values
* represented by the histogram. We have i-1 full bins and
* binfrac partial bin below the constant.
*/
histfrac = (double) (i - 1) + binfrac;
histfrac /= (double) (nvalues - 1);
}
/*
* Now histfrac = fraction of histogram entries below the
* constant.
*
* Account for "<" vs ">"
*/
hist_selec = isgt ? (1.0 - histfrac) : histfrac;
/*
* The histogram boundaries are only approximate to begin with,
* and may well be out of date anyway. Therefore, don't believe
* extremely small or large selectivity estimates --- unless we
* got actual current endpoint values from the table.
*/
if (have_end)
CLAMP_PROBABILITY(hist_selec);
else
{
if (hist_selec < 0.0001)
hist_selec = 0.0001;
else if (hist_selec > 0.9999)
hist_selec = 0.9999;
}
}
free_attstatsslot(vardata->atttype, values, nvalues, NULL, 0);
}
return hist_selec;
}
| static Pattern_Prefix_Status like_fixed_prefix | ( | Const * | patt_const, | |
| bool | case_insensitive, | |||
| Oid | collation, | |||
| Const ** | prefix_const, | |||
| Selectivity * | rest_selec | |||
| ) | [static] |
Definition at line 5151 of file selfuncs.c.
References Assert, BYTEAOID, Const::consttype, Const::constvalue, DatumGetByteaP, DatumGetPointer, DEFAULT_COLLATION_OID, ereport, errcode(), errhint(), errmsg(), ERROR, lc_ctype_is_c(), like_selectivity(), locale, NULL, OidIsValid, palloc(), pattern_char_isalpha(), pfree(), pg_database_encoding_max_length(), pg_newlocale_from_collation(), string_to_bytea_const(), string_to_const(), TextDatumGetCString, TEXTOID, VARDATA, and VARSIZE.
Referenced by pattern_fixed_prefix().
{
char *match;
char *patt;
int pattlen;
Oid typeid = patt_const->consttype;
int pos,
match_pos;
bool is_multibyte = (pg_database_encoding_max_length() > 1);
pg_locale_t locale = 0;
bool locale_is_c = false;
/* the right-hand const is type text or bytea */
Assert(typeid == BYTEAOID || typeid == TEXTOID);
if (case_insensitive)
{
if (typeid == BYTEAOID)
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("case insensitive matching not supported on type bytea")));
/* If case-insensitive, we need locale info */
if (lc_ctype_is_c(collation))
locale_is_c = true;
else if (collation != DEFAULT_COLLATION_OID)
{
if (!OidIsValid(collation))
{
/*
* This typically means that the parser could not resolve a
* conflict of implicit collations, so report it that way.
*/
ereport(ERROR,
(errcode(ERRCODE_INDETERMINATE_COLLATION),
errmsg("could not determine which collation to use for ILIKE"),
errhint("Use the COLLATE clause to set the collation explicitly.")));
}
locale = pg_newlocale_from_collation(collation);
}
}
if (typeid != BYTEAOID)
{
patt = TextDatumGetCString(patt_const->constvalue);
pattlen = strlen(patt);
}
else
{
bytea *bstr = DatumGetByteaP(patt_const->constvalue);
pattlen = VARSIZE(bstr) - VARHDRSZ;
patt = (char *) palloc(pattlen);
memcpy(patt, VARDATA(bstr), pattlen);
if ((Pointer) bstr != DatumGetPointer(patt_const->constvalue))
pfree(bstr);
}
match = palloc(pattlen + 1);
match_pos = 0;
for (pos = 0; pos < pattlen; pos++)
{
/* % and _ are wildcard characters in LIKE */
if (patt[pos] == '%' ||
patt[pos] == '_')
break;
/* Backslash escapes the next character */
if (patt[pos] == '\\')
{
pos++;
if (pos >= pattlen)
break;
}
/* Stop if case-varying character (it's sort of a wildcard) */
if (case_insensitive &&
pattern_char_isalpha(patt[pos], is_multibyte, locale, locale_is_c))
break;
match[match_pos++] = patt[pos];
}
match[match_pos] = '\0';
if (typeid != BYTEAOID)
*prefix_const = string_to_const(match, typeid);
else
*prefix_const = string_to_bytea_const(match, match_pos);
if (rest_selec != NULL)
*rest_selec = like_selectivity(&patt[pos], pattlen - pos,
case_insensitive);
pfree(patt);
pfree(match);
/* in LIKE, an empty pattern is an exact match! */
if (pos == pattlen)
return Pattern_Prefix_Exact; /* reached end of pattern, so exact */
if (match_pos > 0)
return Pattern_Prefix_Partial;
return Pattern_Prefix_None;
}
| static Selectivity like_selectivity | ( | const char * | patt, | |
| int | pattlen, | |||
| bool | case_insensitive | |||
| ) | [static] |
Definition at line 5479 of file selfuncs.c.
Referenced by like_fixed_prefix().
{
Selectivity sel = 1.0;
int pos;
/* Skip any leading wildcard; it's already factored into initial sel */
for (pos = 0; pos < pattlen; pos++)
{
if (patt[pos] != '%' && patt[pos] != '_')
break;
}
for (; pos < pattlen; pos++)
{
/* % and _ are wildcard characters in LIKE */
if (patt[pos] == '%')
sel *= FULL_WILDCARD_SEL;
else if (patt[pos] == '_')
sel *= ANY_CHAR_SEL;
else if (patt[pos] == '\\')
{
/* Backslash quotes the next character */
pos++;
if (pos >= pattlen)
break;
sel *= FIXED_CHAR_SEL;
}
else
sel *= FIXED_CHAR_SEL;
}
/* Could get sel > 1 if multiple wildcards */
if (sel > 1.0)
sel = 1.0;
return sel;
}
| Datum likejoinsel | ( | PG_FUNCTION_ARGS | ) |
Definition at line 2712 of file selfuncs.c.
References Pattern_Type_Like, patternjoinsel(), and PG_RETURN_FLOAT8.
{
PG_RETURN_FLOAT8(patternjoinsel(fcinfo, Pattern_Type_Like, false));
}
| Datum likesel | ( | PG_FUNCTION_ARGS | ) |
Definition at line 1392 of file selfuncs.c.
References Pattern_Type_Like, patternsel(), and PG_RETURN_FLOAT8.
{
PG_RETURN_FLOAT8(patternsel(fcinfo, Pattern_Type_Like, false));
}
Definition at line 5693 of file selfuncs.c.
References BYTEAOID, Const::consttype, Const::constvalue, DatumGetBool, DatumGetByteaP, DatumGetCString, DatumGetPointer, DirectFunctionCall1, FunctionCall2Coll(), lc_collate_is_c(), NAMEOID, nameout(), palloc(), pfree(), pg_database_encoding_character_incrementer(), pg_mbcliplen(), PointerGetDatum, SET_VARSIZE, string_to_bytea_const(), string_to_const(), TextDatumGetCString, VARDATA, VARHDRSZ, VARSIZE, and varstr_cmp().
Referenced by prefix_quals(), and prefix_selectivity().
{
Oid datatype = str_const->consttype;
char *workstr;
int len;
Datum cmpstr;
text *cmptxt = NULL;
mbcharacter_incrementer charinc;
/*
* Get a modifiable copy of the prefix string in C-string format, and set
* up the string we will compare to as a Datum. In C locale this can just
* be the given prefix string, otherwise we need to add a suffix. Types
* NAME and BYTEA sort bytewise so they don't need a suffix either.
*/
if (datatype == NAMEOID)
{
workstr = DatumGetCString(DirectFunctionCall1(nameout,
str_const->constvalue));
len = strlen(workstr);
cmpstr = str_const->constvalue;
}
else if (datatype == BYTEAOID)
{
bytea *bstr = DatumGetByteaP(str_const->constvalue);
len = VARSIZE(bstr) - VARHDRSZ;
workstr = (char *) palloc(len);
memcpy(workstr, VARDATA(bstr), len);
if ((Pointer) bstr != DatumGetPointer(str_const->constvalue))
pfree(bstr);
cmpstr = str_const->constvalue;
}
else
{
workstr = TextDatumGetCString(str_const->constvalue);
len = strlen(workstr);
if (lc_collate_is_c(collation) || len == 0)
cmpstr = str_const->constvalue;
else
{
/* If first time through, determine the suffix to use */
static char suffixchar = 0;
static Oid suffixcollation = 0;
if (!suffixchar || suffixcollation != collation)
{
char *best;
best = "Z";
if (varstr_cmp(best, 1, "z", 1, collation) < 0)
best = "z";
if (varstr_cmp(best, 1, "y", 1, collation) < 0)
best = "y";
if (varstr_cmp(best, 1, "9", 1, collation) < 0)
best = "9";
suffixchar = *best;
suffixcollation = collation;
}
/* And build the string to compare to */
cmptxt = (text *) palloc(VARHDRSZ + len + 1);
SET_VARSIZE(cmptxt, VARHDRSZ + len + 1);
memcpy(VARDATA(cmptxt), workstr, len);
*(VARDATA(cmptxt) + len) = suffixchar;
cmpstr = PointerGetDatum(cmptxt);
}
}
/* Select appropriate character-incrementer function */
if (datatype == BYTEAOID)
charinc = byte_increment;
else
charinc = pg_database_encoding_character_incrementer();
/* And search ... */
while (len > 0)
{
int charlen;
unsigned char *lastchar;
/* Identify the last character --- for bytea, just the last byte */
if (datatype == BYTEAOID)
charlen = 1;
else
charlen = len - pg_mbcliplen(workstr, len, len - 1);
lastchar = (unsigned char *) (workstr + len - charlen);
/*
* Try to generate a larger string by incrementing the last character
* (for BYTEA, we treat each byte as a character).
*
* Note: the incrementer function is expected to return true if it's
* generated a valid-per-the-encoding new character, otherwise false.
* The contents of the character on false return are unspecified.
*/
while (charinc(lastchar, charlen))
{
Const *workstr_const;
if (datatype == BYTEAOID)
workstr_const = string_to_bytea_const(workstr, len);
else
workstr_const = string_to_const(workstr, datatype);
if (DatumGetBool(FunctionCall2Coll(ltproc,
collation,
cmpstr,
workstr_const->constvalue)))
{
/* Successfully made a string larger than cmpstr */
if (cmptxt)
pfree(cmptxt);
pfree(workstr);
return workstr_const;
}
/* No good, release unusable value and try again */
pfree(DatumGetPointer(workstr_const->constvalue));
pfree(workstr_const);
}
/*
* No luck here, so truncate off the last character and try to
* increment the next one.
*/
len -= charlen;
workstr[len] = '\0';
}
/* Failed... */
if (cmptxt)
pfree(cmptxt);
pfree(workstr);
return NULL;
}
| double mcv_selectivity | ( | VariableStatData * | vardata, | |
| FmgrInfo * | opproc, | |||
| Datum | constval, | |||
| bool | varonleft, | |||
| double * | sumcommonp | |||
| ) |
Definition at line 602 of file selfuncs.c.
References VariableStatData::atttype, VariableStatData::atttypmod, DatumGetBool, DEFAULT_COLLATION_OID, free_attstatsslot(), FunctionCall2Coll(), get_attstatsslot(), HeapTupleIsValid, i, InvalidOid, NULL, STATISTIC_KIND_MCV, VariableStatData::statsTuple, and values.
Referenced by ltreeparentsel(), patternsel(), and scalarineqsel().
{
double mcv_selec,
sumcommon;
Datum *values;
int nvalues;
float4 *numbers;
int nnumbers;
int i;
mcv_selec = 0.0;
sumcommon = 0.0;
if (HeapTupleIsValid(vardata->statsTuple) &&
get_attstatsslot(vardata->statsTuple,
vardata->atttype, vardata->atttypmod,
STATISTIC_KIND_MCV, InvalidOid,
NULL,
&values, &nvalues,
&numbers, &nnumbers))
{
for (i = 0; i < nvalues; i++)
{
if (varonleft ?
DatumGetBool(FunctionCall2Coll(opproc,
DEFAULT_COLLATION_OID,
values[i],
constval)) :
DatumGetBool(FunctionCall2Coll(opproc,
DEFAULT_COLLATION_OID,
constval,
values[i])))
mcv_selec += numbers[i];
sumcommon += numbers[i];
}
free_attstatsslot(vardata->atttype, values, nvalues,
numbers, nnumbers);
}
*sumcommonp = sumcommon;
return mcv_selec;
}
| void mergejoinscansel | ( | PlannerInfo * | root, | |
| Node * | clause, | |||
| Oid | opfamily, | |||
| int | strategy, | |||
| bool | nulls_first, | |||
| Selectivity * | leftstart, | |||
| Selectivity * | leftend, | |||
| Selectivity * | rightstart, | |||
| Selectivity * | rightend | |||
| ) |
Definition at line 2784 of file selfuncs.c.
References Assert, BTEqualStrategyNumber, BTGreaterEqualStrategyNumber, BTGreaterStrategyNumber, BTLessEqualStrategyNumber, BTLessStrategyNumber, CLAMP_PROBABILITY, DEFAULT_INEQ_SEL, examine_variable(), get_leftop(), get_op_opfamily_properties(), get_opfamily_member(), get_rightop(), get_variable_range(), GETSTRUCT, HeapTupleIsValid, is_opclause, OidIsValid, ReleaseVariableStats, scalarineqsel(), and VariableStatData::statsTuple.
Referenced by cached_scansel().
{
Node *left,
*right;
VariableStatData leftvar,
rightvar;
int op_strategy;
Oid op_lefttype;
Oid op_righttype;
Oid opno,
lsortop,
rsortop,
lstatop,
rstatop,
ltop,
leop,
revltop,
revleop;
bool isgt;
Datum leftmin,
leftmax,
rightmin,
rightmax;
double selec;
/* Set default results if we can't figure anything out. */
/* XXX should default "start" fraction be a bit more than 0? */
*leftstart = *rightstart = 0.0;
*leftend = *rightend = 1.0;
/* Deconstruct the merge clause */
if (!is_opclause(clause))
return; /* shouldn't happen */
opno = ((OpExpr *) clause)->opno;
left = get_leftop((Expr *) clause);
right = get_rightop((Expr *) clause);
if (!right)
return; /* shouldn't happen */
/* Look for stats for the inputs */
examine_variable(root, left, 0, &leftvar);
examine_variable(root, right, 0, &rightvar);
/* Extract the operator's declared left/right datatypes */
get_op_opfamily_properties(opno, opfamily, false,
&op_strategy,
&op_lefttype,
&op_righttype);
Assert(op_strategy == BTEqualStrategyNumber);
/*
* Look up the various operators we need. If we don't find them all, it
* probably means the opfamily is broken, but we just fail silently.
*
* Note: we expect that pg_statistic histograms will be sorted by the '<'
* operator, regardless of which sort direction we are considering.
*/
switch (strategy)
{
case BTLessStrategyNumber:
isgt = false;
if (op_lefttype == op_righttype)
{
/* easy case */
ltop = get_opfamily_member(opfamily,
op_lefttype, op_righttype,
BTLessStrategyNumber);
leop = get_opfamily_member(opfamily,
op_lefttype, op_righttype,
BTLessEqualStrategyNumber);
lsortop = ltop;
rsortop = ltop;
lstatop = lsortop;
rstatop = rsortop;
revltop = ltop;
revleop = leop;
}
else
{
ltop = get_opfamily_member(opfamily,
op_lefttype, op_righttype,
BTLessStrategyNumber);
leop = get_opfamily_member(opfamily,
op_lefttype, op_righttype,
BTLessEqualStrategyNumber);
lsortop = get_opfamily_member(opfamily,
op_lefttype, op_lefttype,
BTLessStrategyNumber);
rsortop = get_opfamily_member(opfamily,
op_righttype, op_righttype,
BTLessStrategyNumber);
lstatop = lsortop;
rstatop = rsortop;
revltop = get_opfamily_member(opfamily,
op_righttype, op_lefttype,
BTLessStrategyNumber);
revleop = get_opfamily_member(opfamily,
op_righttype, op_lefttype,
BTLessEqualStrategyNumber);
}
break;
case BTGreaterStrategyNumber:
/* descending-order case */
isgt = true;
if (op_lefttype == op_righttype)
{
/* easy case */
ltop = get_opfamily_member(opfamily,
op_lefttype, op_righttype,
BTGreaterStrategyNumber);
leop = get_opfamily_member(opfamily,
op_lefttype, op_righttype,
BTGreaterEqualStrategyNumber);
lsortop = ltop;
rsortop = ltop;
lstatop = get_opfamily_member(opfamily,
op_lefttype, op_lefttype,
BTLessStrategyNumber);
rstatop = lstatop;
revltop = ltop;
revleop = leop;
}
else
{
ltop = get_opfamily_member(opfamily,
op_lefttype, op_righttype,
BTGreaterStrategyNumber);
leop = get_opfamily_member(opfamily,
op_lefttype, op_righttype,
BTGreaterEqualStrategyNumber);
lsortop = get_opfamily_member(opfamily,
op_lefttype, op_lefttype,
BTGreaterStrategyNumber);
rsortop = get_opfamily_member(opfamily,
op_righttype, op_righttype,
BTGreaterStrategyNumber);
lstatop = get_opfamily_member(opfamily,
op_lefttype, op_lefttype,
BTLessStrategyNumber);
rstatop = get_opfamily_member(opfamily,
op_righttype, op_righttype,
BTLessStrategyNumber);
revltop = get_opfamily_member(opfamily,
op_righttype, op_lefttype,
BTGreaterStrategyNumber);
revleop = get_opfamily_member(opfamily,
op_righttype, op_lefttype,
BTGreaterEqualStrategyNumber);
}
break;
default:
goto fail; /* shouldn't get here */
}
if (!OidIsValid(lsortop) ||
!OidIsValid(rsortop) ||
!OidIsValid(lstatop) ||
!OidIsValid(rstatop) ||
!OidIsValid(ltop) ||
!OidIsValid(leop) ||
!OidIsValid(revltop) ||
!OidIsValid(revleop))
goto fail; /* insufficient info in catalogs */
/* Try to get ranges of both inputs */
if (!isgt)
{
if (!get_variable_range(root, &leftvar, lstatop,
&leftmin, &leftmax))
goto fail; /* no range available from stats */
if (!get_variable_range(root, &rightvar, rstatop,
&rightmin, &rightmax))
goto fail; /* no range available from stats */
}
else
{
/* need to swap the max and min */
if (!get_variable_range(root, &leftvar, lstatop,
&leftmax, &leftmin))
goto fail; /* no range available from stats */
if (!get_variable_range(root, &rightvar, rstatop,
&rightmax, &rightmin))
goto fail; /* no range available from stats */
}
/*
* Now, the fraction of the left variable that will be scanned is the
* fraction that's <= the right-side maximum value. But only believe
* non-default estimates, else stick with our 1.0.
*/
selec = scalarineqsel(root, leop, isgt, &leftvar,
rightmax, op_righttype);
if (selec != DEFAULT_INEQ_SEL)
*leftend = selec;
/* And similarly for the right variable. */
selec = scalarineqsel(root, revleop, isgt, &rightvar,
leftmax, op_lefttype);
if (selec != DEFAULT_INEQ_SEL)
*rightend = selec;
/*
* Only one of the two "end" fractions can really be less than 1.0;
* believe the smaller estimate and reset the other one to exactly 1.0. If
* we get exactly equal estimates (as can easily happen with self-joins),
* believe neither.
*/
if (*leftend > *rightend)
*leftend = 1.0;
else if (*leftend < *rightend)
*rightend = 1.0;
else
*leftend = *rightend = 1.0;
/*
* Also, the fraction of the left variable that will be scanned before the
* first join pair is found is the fraction that's < the right-side
* minimum value. But only believe non-default estimates, else stick with
* our own default.
*/
selec = scalarineqsel(root, ltop, isgt, &leftvar,
rightmin, op_righttype);
if (selec != DEFAULT_INEQ_SEL)
*leftstart = selec;
/* And similarly for the right variable. */
selec = scalarineqsel(root, revltop, isgt, &rightvar,
leftmin, op_lefttype);
if (selec != DEFAULT_INEQ_SEL)
*rightstart = selec;
/*
* Only one of the two "start" fractions can really be more than zero;
* believe the larger estimate and reset the other one to exactly 0.0. If
* we get exactly equal estimates (as can easily happen with self-joins),
* believe neither.
*/
if (*leftstart < *rightstart)
*leftstart = 0.0;
else if (*leftstart > *rightstart)
*rightstart = 0.0;
else
*leftstart = *rightstart = 0.0;
/*
* If the sort order is nulls-first, we're going to have to skip over any
* nulls too. These would not have been counted by scalarineqsel, and we
* can safely add in this fraction regardless of whether we believe
* scalarineqsel's results or not. But be sure to clamp the sum to 1.0!
*/
if (nulls_first)
{
Form_pg_statistic stats;
if (HeapTupleIsValid(leftvar.statsTuple))
{
stats = (Form_pg_statistic) GETSTRUCT(leftvar.statsTuple);
*leftstart += stats->stanullfrac;
CLAMP_PROBABILITY(*leftstart);
*leftend += stats->stanullfrac;
CLAMP_PROBABILITY(*leftend);
}
if (HeapTupleIsValid(rightvar.statsTuple))
{
stats = (Form_pg_statistic) GETSTRUCT(rightvar.statsTuple);
*rightstart += stats->stanullfrac;
CLAMP_PROBABILITY(*rightstart);
*rightend += stats->stanullfrac;
CLAMP_PROBABILITY(*rightend);
}
}
/* Disbelieve start >= end, just in case that can happen */
if (*leftstart >= *leftend)
{
*leftstart = 0.0;
*leftend = 1.0;
}
if (*rightstart >= *rightend)
{
*rightstart = 0.0;
*rightend = 1.0;
}
fail:
ReleaseVariableStats(leftvar);
ReleaseVariableStats(rightvar);
}
| Datum neqjoinsel | ( | PG_FUNCTION_ARGS | ) |
Definition at line 2629 of file selfuncs.c.
References DatumGetFloat8, DirectFunctionCall5, eqjoinsel(), get_negator(), Int16GetDatum, ObjectIdGetDatum, PG_GETARG_INT16, PG_GETARG_POINTER, PG_RETURN_FLOAT8, and PointerGetDatum.
{
PlannerInfo *root = (PlannerInfo *) PG_GETARG_POINTER(0);
Oid operator = PG_GETARG_OID(1);
List *args = (List *) PG_GETARG_POINTER(2);
JoinType jointype = (JoinType) PG_GETARG_INT16(3);
SpecialJoinInfo *sjinfo = (SpecialJoinInfo *) PG_GETARG_POINTER(4);
Oid eqop;
float8 result;
/*
* We want 1 - eqjoinsel() where the equality operator is the one
* associated with this != operator, that is, its negator.
*/
eqop = get_negator(operator);
if (eqop)
{
result = DatumGetFloat8(DirectFunctionCall5(eqjoinsel,
PointerGetDatum(root),
ObjectIdGetDatum(eqop),
PointerGetDatum(args),
Int16GetDatum(jointype),
PointerGetDatum(sjinfo)));
}
else
{
/* Use default selectivity (should we raise an error instead?) */
result = DEFAULT_EQ_SEL;
}
result = 1.0 - result;
PG_RETURN_FLOAT8(result);
}
| Datum neqsel | ( | PG_FUNCTION_ARGS | ) |
Definition at line 483 of file selfuncs.c.
References DatumGetFloat8, DirectFunctionCall4, eqsel(), get_negator(), Int32GetDatum, ObjectIdGetDatum, PG_GETARG_INT32, PG_GETARG_POINTER, PG_RETURN_FLOAT8, and PointerGetDatum.
{
PlannerInfo *root = (PlannerInfo *) PG_GETARG_POINTER(0);
Oid operator = PG_GETARG_OID(1);
List *args = (List *) PG_GETARG_POINTER(2);
int varRelid = PG_GETARG_INT32(3);
Oid eqop;
float8 result;
/*
* We want 1 - eqsel() where the equality operator is the one associated
* with this != operator, that is, its negator.
*/
eqop = get_negator(operator);
if (eqop)
{
result = DatumGetFloat8(DirectFunctionCall4(eqsel,
PointerGetDatum(root),
ObjectIdGetDatum(eqop),
PointerGetDatum(args),
Int32GetDatum(varRelid)));
}
else
{
/* Use default selectivity (should we raise an error instead?) */
result = DEFAULT_EQ_SEL;
}
result = 1.0 - result;
PG_RETURN_FLOAT8(result);
}
| Datum nlikejoinsel | ( | PG_FUNCTION_ARGS | ) |
Definition at line 2748 of file selfuncs.c.
References Pattern_Type_Like, patternjoinsel(), and PG_RETURN_FLOAT8.
{
PG_RETURN_FLOAT8(patternjoinsel(fcinfo, Pattern_Type_Like, true));
}
| Datum nlikesel | ( | PG_FUNCTION_ARGS | ) |
Definition at line 1428 of file selfuncs.c.
References Pattern_Type_Like, patternsel(), and PG_RETURN_FLOAT8.
{
PG_RETURN_FLOAT8(patternsel(fcinfo, Pattern_Type_Like, true));
}
| Selectivity nulltestsel | ( | PlannerInfo * | root, | |
| NullTestType | nulltesttype, | |||
| Node * | arg, | |||
| int | varRelid, | |||
| JoinType | jointype, | |||
| SpecialJoinInfo * | sjinfo | |||
| ) |
Definition at line 1613 of file selfuncs.c.
References CLAMP_PROBABILITY, elog, ERROR, examine_variable(), GETSTRUCT, HeapTupleIsValid, IS_NOT_NULL, IS_NULL, ReleaseVariableStats, and VariableStatData::statsTuple.
Referenced by clause_selectivity(), and clauselist_selectivity().
{
VariableStatData vardata;
double selec;
examine_variable(root, arg, varRelid, &vardata);
if (HeapTupleIsValid(vardata.statsTuple))
{
Form_pg_statistic stats;
double freq_null;
stats = (Form_pg_statistic) GETSTRUCT(vardata.statsTuple);
freq_null = stats->stanullfrac;
switch (nulltesttype)
{
case IS_NULL:
/*
* Use freq_null directly.
*/
selec = freq_null;
break;
case IS_NOT_NULL:
/*
* Select not unknown (not null) values. Calculate from
* freq_null.
*/
selec = 1.0 - freq_null;
break;
default:
elog(ERROR, "unrecognized nulltesttype: %d",
(int) nulltesttype);
return (Selectivity) 0; /* keep compiler quiet */
}
}
else
{
/*
* No ANALYZE stats available, so make a guess
*/
switch (nulltesttype)
{
case IS_NULL:
selec = DEFAULT_UNK_SEL;
break;
case IS_NOT_NULL:
selec = DEFAULT_NOT_UNK_SEL;
break;
default:
elog(ERROR, "unrecognized nulltesttype: %d",
(int) nulltesttype);
return (Selectivity) 0; /* keep compiler quiet */
}
}
ReleaseVariableStats(vardata);
/* result should be in range, but make sure... */
CLAMP_PROBABILITY(selec);
return (Selectivity) selec;
}
| static int pattern_char_isalpha | ( | char | c, | |
| bool | is_multibyte, | |||
| pg_locale_t | locale, | |||
| bool | locale_is_c | |||
| ) | [static] |
Definition at line 5122 of file selfuncs.c.
References IS_HIGHBIT_SET, and isalpha_l.
Referenced by like_fixed_prefix().
| Pattern_Prefix_Status pattern_fixed_prefix | ( | Const * | patt, | |
| Pattern_Type | ptype, | |||
| Oid | collation, | |||
| Const ** | prefix, | |||
| Selectivity * | rest_selec | |||
| ) |
Definition at line 5328 of file selfuncs.c.
References elog, ERROR, like_fixed_prefix(), Pattern_Type_Like, Pattern_Type_Like_IC, Pattern_Type_Regex, Pattern_Type_Regex_IC, and regex_fixed_prefix().
Referenced by expand_indexqual_opclause(), match_special_index_operator(), and patternsel().
{
Pattern_Prefix_Status result;
switch (ptype)
{
case Pattern_Type_Like:
result = like_fixed_prefix(patt, false, collation,
prefix, rest_selec);
break;
case Pattern_Type_Like_IC:
result = like_fixed_prefix(patt, true, collation,
prefix, rest_selec);
break;
case Pattern_Type_Regex:
result = regex_fixed_prefix(patt, false, collation,
prefix, rest_selec);
break;
case Pattern_Type_Regex_IC:
result = regex_fixed_prefix(patt, true, collation,
prefix, rest_selec);
break;
default:
elog(ERROR, "unrecognized ptype: %d", (int) ptype);
result = Pattern_Prefix_None; /* keep compiler quiet */
break;
}
return result;
}
| static double patternjoinsel | ( | PG_FUNCTION_ARGS | , | |
| Pattern_Type | ptype, | |||
| bool | negate | |||
| ) | [static] |
Definition at line 2684 of file selfuncs.c.
References DEFAULT_MATCH_SEL.
Referenced by iclikejoinsel(), icnlikejoinsel(), icregexeqjoinsel(), icregexnejoinsel(), likejoinsel(), nlikejoinsel(), regexeqjoinsel(), and regexnejoinsel().
{
/* For the moment we just punt. */
return negate ? (1.0 - DEFAULT_MATCH_SEL) : DEFAULT_MATCH_SEL;
}
| static double patternsel | ( | PG_FUNCTION_ARGS | , | |
| Pattern_Type | ptype, | |||
| bool | negate | |||
| ) | [static] |
Definition at line 1109 of file selfuncs.c.
References BPCHAROID, BTEqualStrategyNumber, BYTEAOID, byteaout(), CLAMP_PROBABILITY, Const::consttype, Const::constvalue, DatumGetCString, DatumGetPointer, DirectFunctionCall1, elog, ERROR, fmgr_info(), get_opcode(), get_opfamily_member(), get_restriction_variable(), GETSTRUCT, HeapTupleIsValid, histogram_selectivity(), InvalidOid, IsA, mcv_selectivity(), NAMEOID, OidIsValid, pattern_fixed_prefix(), Pattern_Prefix_Exact, Pattern_Prefix_Partial, pfree(), PG_GET_COLLATION, PG_GETARG_INT32, PG_GETARG_POINTER, prefix_selectivity(), ReleaseVariableStats, VariableStatData::statsTuple, string_to_const(), TextDatumGetCString, TEXTOID, var_eq_const(), and VariableStatData::vartype.
Referenced by iclikesel(), icnlikesel(), icregexeqsel(), icregexnesel(), likesel(), nlikesel(), regexeqsel(), and regexnesel().
{
PlannerInfo *root = (PlannerInfo *) PG_GETARG_POINTER(0);
Oid operator = PG_GETARG_OID(1);
List *args = (List *) PG_GETARG_POINTER(2);
int varRelid = PG_GETARG_INT32(3);
Oid collation = PG_GET_COLLATION();
VariableStatData vardata;
Node *other;
bool varonleft;
Datum constval;
Oid consttype;
Oid vartype;
Oid opfamily;
Pattern_Prefix_Status pstatus;
Const *patt;
Const *prefix = NULL;
Selectivity rest_selec = 0;
double result;
/*
* If this is for a NOT LIKE or similar operator, get the corresponding
* positive-match operator and work with that. Set result to the correct
* default estimate, too.
*/
if (negate)
{
operator = get_negator(operator);
if (!OidIsValid(operator))
elog(ERROR, "patternsel called for operator without a negator");
result = 1.0 - DEFAULT_MATCH_SEL;
}
else
{
result = DEFAULT_MATCH_SEL;
}
/*
* If expression is not variable op constant, then punt and return a
* default estimate.
*/
if (!get_restriction_variable(root, args, varRelid,
&vardata, &other, &varonleft))
return result;
if (!varonleft || !IsA(other, Const))
{
ReleaseVariableStats(vardata);
return result;
}
/*
* If the constant is NULL, assume operator is strict and return zero, ie,
* operator will never return TRUE. (It's zero even for a negator op.)
*/
if (((Const *) other)->constisnull)
{
ReleaseVariableStats(vardata);
return 0.0;
}
constval = ((Const *) other)->constvalue;
consttype = ((Const *) other)->consttype;
/*
* The right-hand const is type text or bytea for all supported operators.
* We do not expect to see binary-compatible types here, since
* const-folding should have relabeled the const to exactly match the
* operator's declared type.
*/
if (consttype != TEXTOID && consttype != BYTEAOID)
{
ReleaseVariableStats(vardata);
return result;
}
/*
* Similarly, the exposed type of the left-hand side should be one of
* those we know. (Do not look at vardata.atttype, which might be
* something binary-compatible but different.) We can use it to choose
* the index opfamily from which we must draw the comparison operators.
*
* NOTE: It would be more correct to use the PATTERN opfamilies than the
* simple ones, but at the moment ANALYZE will not generate statistics for
* the PATTERN operators. But our results are so approximate anyway that
* it probably hardly matters.
*/
vartype = vardata.vartype;
switch (vartype)
{
case TEXTOID:
opfamily = TEXT_BTREE_FAM_OID;
break;
case BPCHAROID:
opfamily = BPCHAR_BTREE_FAM_OID;
break;
case NAMEOID:
opfamily = NAME_BTREE_FAM_OID;
break;
case BYTEAOID:
opfamily = BYTEA_BTREE_FAM_OID;
break;
default:
ReleaseVariableStats(vardata);
return result;
}
/*
* Pull out any fixed prefix implied by the pattern, and estimate the
* fractional selectivity of the remainder of the pattern. Unlike many of
* the other functions in this file, we use the pattern operator's actual
* collation for this step. This is not because we expect the collation
* to make a big difference in the selectivity estimate (it seldom would),
* but because we want to be sure we cache compiled regexps under the
* right cache key, so that they can be re-used at runtime.
*/
patt = (Const *) other;
pstatus = pattern_fixed_prefix(patt, ptype, collation,
&prefix, &rest_selec);
/*
* If necessary, coerce the prefix constant to the right type.
*/
if (prefix && prefix->consttype != vartype)
{
char *prefixstr;
switch (prefix->consttype)
{
case TEXTOID:
prefixstr = TextDatumGetCString(prefix->constvalue);
break;
case BYTEAOID:
prefixstr = DatumGetCString(DirectFunctionCall1(byteaout,
prefix->constvalue));
break;
default:
elog(ERROR, "unrecognized consttype: %u",
prefix->consttype);
ReleaseVariableStats(vardata);
return result;
}
prefix = string_to_const(prefixstr, vartype);
pfree(prefixstr);
}
if (pstatus == Pattern_Prefix_Exact)
{
/*
* Pattern specifies an exact match, so pretend operator is '='
*/
Oid eqopr = get_opfamily_member(opfamily, vartype, vartype,
BTEqualStrategyNumber);
if (eqopr == InvalidOid)
elog(ERROR, "no = operator for opfamily %u", opfamily);
result = var_eq_const(&vardata, eqopr, prefix->constvalue,
false, true);
}
else
{
/*
* Not exact-match pattern. If we have a sufficiently large
* histogram, estimate selectivity for the histogram part of the
* population by counting matches in the histogram. If not, estimate
* selectivity of the fixed prefix and remainder of pattern
* separately, then combine the two to get an estimate of the
* selectivity for the part of the column population represented by
* the histogram. (For small histograms, we combine these
* approaches.)
*
* We then add up data for any most-common-values values; these are
* not in the histogram population, and we can get exact answers for
* them by applying the pattern operator, so there's no reason to
* approximate. (If the MCVs cover a significant part of the total
* population, this gives us a big leg up in accuracy.)
*/
Selectivity selec;
int hist_size;
FmgrInfo opproc;
double nullfrac,
mcv_selec,
sumcommon;
/* Try to use the histogram entries to get selectivity */
fmgr_info(get_opcode(operator), &opproc);
selec = histogram_selectivity(&vardata, &opproc, constval, true,
10, 1, &hist_size);
/* If not at least 100 entries, use the heuristic method */
if (hist_size < 100)
{
Selectivity heursel;
Selectivity prefixsel;
if (pstatus == Pattern_Prefix_Partial)
prefixsel = prefix_selectivity(root, &vardata, vartype,
opfamily, prefix);
else
prefixsel = 1.0;
heursel = prefixsel * rest_selec;
if (selec < 0) /* fewer than 10 histogram entries? */
selec = heursel;
else
{
/*
* For histogram sizes from 10 to 100, we combine the
* histogram and heuristic selectivities, putting increasingly
* more trust in the histogram for larger sizes.
*/
double hist_weight = hist_size / 100.0;
selec = selec * hist_weight + heursel * (1.0 - hist_weight);
}
}
/* In any case, don't believe extremely small or large estimates. */
if (selec < 0.0001)
selec = 0.0001;
else if (selec > 0.9999)
selec = 0.9999;
/*
* If we have most-common-values info, add up the fractions of the MCV
* entries that satisfy MCV OP PATTERN. These fractions contribute
* directly to the result selectivity. Also add up the total fraction
* represented by MCV entries.
*/
mcv_selec = mcv_selectivity(&vardata, &opproc, constval, true,
&sumcommon);
if (HeapTupleIsValid(vardata.statsTuple))
nullfrac = ((Form_pg_statistic) GETSTRUCT(vardata.statsTuple))->stanullfrac;
else
nullfrac = 0.0;
/*
* Now merge the results from the MCV and histogram calculations,
* realizing that the histogram covers only the non-null values that
* are not listed in MCV.
*/
selec *= 1.0 - nullfrac - sumcommon;
selec += mcv_selec;
/* result should be in range, but make sure... */
CLAMP_PROBABILITY(selec);
result = selec;
}
if (prefix)
{
pfree(DatumGetPointer(prefix->constvalue));
pfree(prefix);
}
ReleaseVariableStats(vardata);
return negate ? (1.0 - result) : result;
}
| static Selectivity prefix_selectivity | ( | PlannerInfo * | root, | |
| VariableStatData * | vardata, | |||
| Oid | vartype, | |||
| Oid | opfamily, | |||
| Const * | prefixcon | |||
| ) | [static] |
Definition at line 5379 of file selfuncs.c.
References Assert, BTEqualStrategyNumber, BTGreaterEqualStrategyNumber, BTLessStrategyNumber, Const::consttype, Const::constvalue, DEFAULT_COLLATION_OID, elog, ERROR, fmgr_info(), get_opcode(), get_opfamily_member(), ineq_histogram_selectivity(), InvalidOid, make_greater_string(), Max, and var_eq_const().
Referenced by patternsel().
{
Selectivity prefixsel;
Oid cmpopr;
FmgrInfo opproc;
Const *greaterstrcon;
Selectivity eq_sel;
cmpopr = get_opfamily_member(opfamily, vartype, vartype,
BTGreaterEqualStrategyNumber);
if (cmpopr == InvalidOid)
elog(ERROR, "no >= operator for opfamily %u", opfamily);
fmgr_info(get_opcode(cmpopr), &opproc);
prefixsel = ineq_histogram_selectivity(root, vardata, &opproc, true,
prefixcon->constvalue,
prefixcon->consttype);
if (prefixsel < 0.0)
{
/* No histogram is present ... return a suitable default estimate */
return DEFAULT_MATCH_SEL;
}
/*-------
* If we can create a string larger than the prefix, say
* "x < greaterstr".
*-------
*/
cmpopr = get_opfamily_member(opfamily, vartype, vartype,
BTLessStrategyNumber);
if (cmpopr == InvalidOid)
elog(ERROR, "no < operator for opfamily %u", opfamily);
fmgr_info(get_opcode(cmpopr), &opproc);
greaterstrcon = make_greater_string(prefixcon, &opproc,
DEFAULT_COLLATION_OID);
if (greaterstrcon)
{
Selectivity topsel;
topsel = ineq_histogram_selectivity(root, vardata, &opproc, false,
greaterstrcon->constvalue,
greaterstrcon->consttype);
/* ineq_histogram_selectivity worked before, it shouldn't fail now */
Assert(topsel >= 0.0);
/*
* Merge the two selectivities in the same way as for a range query
* (see clauselist_selectivity()). Note that we don't need to worry
* about double-exclusion of nulls, since ineq_histogram_selectivity
* doesn't count those anyway.
*/
prefixsel = topsel + prefixsel - 1.0;
}
/*
* If the prefix is long then the two bounding values might be too close
* together for the histogram to distinguish them usefully, resulting in a
* zero estimate (plus or minus roundoff error). To avoid returning a
* ridiculously small estimate, compute the estimated selectivity for
* "variable = 'foo'", and clamp to that. (Obviously, the resultant
* estimate should be at least that.)
*
* We apply this even if we couldn't make a greater string. That case
* suggests that the prefix is near the maximum possible, and thus
* probably off the end of the histogram, and thus we probably got a very
* small estimate from the >= condition; so we still need to clamp.
*/
cmpopr = get_opfamily_member(opfamily, vartype, vartype,
BTEqualStrategyNumber);
if (cmpopr == InvalidOid)
elog(ERROR, "no = operator for opfamily %u", opfamily);
eq_sel = var_eq_const(vardata, cmpopr, prefixcon->constvalue,
false, true);
prefixsel = Max(prefixsel, eq_sel);
return prefixsel;
}
| static Pattern_Prefix_Status regex_fixed_prefix | ( | Const * | patt_const, | |
| bool | case_insensitive, | |||
| Oid | collation, | |||
| Const ** | prefix_const, | |||
| Selectivity * | rest_selec | |||
| ) | [static] |
Definition at line 5260 of file selfuncs.c.
References BYTEAOID, Const::consttype, Const::constvalue, DatumGetTextPP, ereport, errcode(), errmsg(), ERROR, NULL, pfree(), regex_selectivity(), regexp_fixed_prefix(), string_to_const(), and TextDatumGetCString.
Referenced by pattern_fixed_prefix().
{
Oid typeid = patt_const->consttype;
char *prefix;
bool exact;
/*
* Should be unnecessary, there are no bytea regex operators defined. As
* such, it should be noted that the rest of this function has *not* been
* made safe for binary (possibly NULL containing) strings.
*/
if (typeid == BYTEAOID)
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("regular-expression matching not supported on type bytea")));
/* Use the regexp machinery to extract the prefix, if any */
prefix = regexp_fixed_prefix(DatumGetTextPP(patt_const->constvalue),
case_insensitive, collation,
&exact);
if (prefix == NULL)
{
*prefix_const = NULL;
if (rest_selec != NULL)
{
char *patt = TextDatumGetCString(patt_const->constvalue);
*rest_selec = regex_selectivity(patt, strlen(patt),
case_insensitive,
0);
pfree(patt);
}
return Pattern_Prefix_None;
}
*prefix_const = string_to_const(prefix, typeid);
if (rest_selec != NULL)
{
if (exact)
{
/* Exact match, so there's no additional selectivity */
*rest_selec = 1.0;
}
else
{
char *patt = TextDatumGetCString(patt_const->constvalue);
*rest_selec = regex_selectivity(patt, strlen(patt),
case_insensitive,
strlen(prefix));
pfree(patt);
}
}
pfree(prefix);
if (exact)
return Pattern_Prefix_Exact; /* pattern specifies exact match */
else
return Pattern_Prefix_Partial;
}
| static Selectivity regex_selectivity | ( | const char * | patt, | |
| int | pattlen, | |||
| bool | case_insensitive, | |||
| int | fixed_prefix_len | |||
| ) | [static] |
Definition at line 5609 of file selfuncs.c.
References CLAMP_PROBABILITY, FIXED_CHAR_SEL, and regex_selectivity_sub().
Referenced by regex_fixed_prefix().
{
Selectivity sel;
/* If patt doesn't end with $, consider it to have a trailing wildcard */
if (pattlen > 0 && patt[pattlen - 1] == '$' &&
(pattlen == 1 || patt[pattlen - 2] != '\\'))
{
/* has trailing $ */
sel = regex_selectivity_sub(patt, pattlen - 1, case_insensitive);
}
else
{
/* no trailing $ */
sel = regex_selectivity_sub(patt, pattlen, case_insensitive);
sel *= FULL_WILDCARD_SEL;
}
/* If there's a fixed prefix, discount its selectivity */
if (fixed_prefix_len > 0)
sel /= pow(FIXED_CHAR_SEL, fixed_prefix_len);
/* Make sure result stays in range */
CLAMP_PROBABILITY(sel);
return sel;
}
| static Selectivity regex_selectivity_sub | ( | const char * | patt, | |
| int | pattlen, | |||
| bool | case_insensitive | |||
| ) | [static] |
Definition at line 5516 of file selfuncs.c.
References CHAR_RANGE_SEL.
Referenced by regex_selectivity().
{
Selectivity sel = 1.0;
int paren_depth = 0;
int paren_pos = 0; /* dummy init to keep compiler quiet */
int pos;
for (pos = 0; pos < pattlen; pos++)
{
if (patt[pos] == '(')
{
if (paren_depth == 0)
paren_pos = pos; /* remember start of parenthesized item */
paren_depth++;
}
else if (patt[pos] == ')' && paren_depth > 0)
{
paren_depth--;
if (paren_depth == 0)
sel *= regex_selectivity_sub(patt + (paren_pos + 1),
pos - (paren_pos + 1),
case_insensitive);
}
else if (patt[pos] == '|' && paren_depth == 0)
{
/*
* If unquoted | is present at paren level 0 in pattern, we have
* multiple alternatives; sum their probabilities.
*/
sel += regex_selectivity_sub(patt + (pos + 1),
pattlen - (pos + 1),
case_insensitive);
break; /* rest of pattern is now processed */
}
else if (patt[pos] == '[')
{
bool negclass = false;
if (patt[++pos] == '^')
{
negclass = true;
pos++;
}
if (patt[pos] == ']') /* ']' at start of class is not
* special */
pos++;
while (pos < pattlen && patt[pos] != ']')
pos++;
if (paren_depth == 0)
sel *= (negclass ? (1.0 - CHAR_RANGE_SEL) : CHAR_RANGE_SEL);
}
else if (patt[pos] == '.')
{
if (paren_depth == 0)
sel *= ANY_CHAR_SEL;
}
else if (patt[pos] == '*' ||
patt[pos] == '?' ||
patt[pos] == '+')
{
/* Ought to be smarter about quantifiers... */
if (paren_depth == 0)
sel *= PARTIAL_WILDCARD_SEL;
}
else if (patt[pos] == '{')
{
while (pos < pattlen && patt[pos] != '}')
pos++;
if (paren_depth == 0)
sel *= PARTIAL_WILDCARD_SEL;
}
else if (patt[pos] == '\\')
{
/* backslash quotes the next character */
pos++;
if (pos >= pattlen)
break;
if (paren_depth == 0)
sel *= FIXED_CHAR_SEL;
}
else
{
if (paren_depth == 0)
sel *= FIXED_CHAR_SEL;
}
}
/* Could get sel > 1 if multiple wildcards */
if (sel > 1.0)
sel = 1.0;
return sel;
}
| Datum regexeqjoinsel | ( | PG_FUNCTION_ARGS | ) |
Definition at line 2694 of file selfuncs.c.
References Pattern_Type_Regex, patternjoinsel(), and PG_RETURN_FLOAT8.
{
PG_RETURN_FLOAT8(patternjoinsel(fcinfo, Pattern_Type_Regex, false));
}
| Datum regexeqsel | ( | PG_FUNCTION_ARGS | ) |
Definition at line 1374 of file selfuncs.c.
References Pattern_Type_Regex, patternsel(), and PG_RETURN_FLOAT8.
{
PG_RETURN_FLOAT8(patternsel(fcinfo, Pattern_Type_Regex, false));
}
| Datum regexnejoinsel | ( | PG_FUNCTION_ARGS | ) |
Definition at line 2730 of file selfuncs.c.
References Pattern_Type_Regex, patternjoinsel(), and PG_RETURN_FLOAT8.
{
PG_RETURN_FLOAT8(patternjoinsel(fcinfo, Pattern_Type_Regex, true));
}
| Datum regexnesel | ( | PG_FUNCTION_ARGS | ) |
Definition at line 1410 of file selfuncs.c.
References Pattern_Type_Regex, patternsel(), and PG_RETURN_FLOAT8.
{
PG_RETURN_FLOAT8(patternsel(fcinfo, Pattern_Type_Regex, true));
}
| Selectivity rowcomparesel | ( | PlannerInfo * | root, | |
| RowCompareExpr * | clause, | |||
| int | varRelid, | |||
| JoinType | jointype, | |||
| SpecialJoinInfo * | sjinfo | |||
| ) |
Definition at line 2066 of file selfuncs.c.
References RowCompareExpr::inputcollids, join_selectivity(), RowCompareExpr::largs, linitial, linitial_oid, list_make2, NULL, NumRelids(), RowCompareExpr::opnos, RowCompareExpr::rargs, restriction_selectivity(), and s1.
Referenced by clause_selectivity().
{
Selectivity s1;
Oid opno = linitial_oid(clause->opnos);
Oid inputcollid = linitial_oid(clause->inputcollids);
List *opargs;
bool is_join_clause;
/* Build equivalent arg list for single operator */
opargs = list_make2(linitial(clause->largs), linitial(clause->rargs));
/*
* Decide if it's a join clause. This should match clausesel.c's
* treat_as_join_clause(), except that we intentionally consider only the
* leading columns and not the rest of the clause.
*/
if (varRelid != 0)
{
/*
* Caller is forcing restriction mode (eg, because we are examining an
* inner indexscan qual).
*/
is_join_clause = false;
}
else if (sjinfo == NULL)
{
/*
* It must be a restriction clause, since it's being evaluated at a
* scan node.
*/
is_join_clause = false;
}
else
{
/*
* Otherwise, it's a join if there's more than one relation used.
*/
is_join_clause = (NumRelids((Node *) opargs) > 1);
}
if (is_join_clause)
{
/* Estimate selectivity for a join clause. */
s1 = join_selectivity(root, opno,
opargs,
inputcollid,
jointype,
sjinfo);
}
else
{
/* Estimate selectivity for a restriction clause. */
s1 = restriction_selectivity(root, opno,
opargs,
inputcollid,
varRelid);
}
return s1;
}
| Selectivity scalararraysel | ( | PlannerInfo * | root, | |
| ScalarArrayOpExpr * | clause, | |||
| bool | is_join_clause, | |||
| int | varRelid, | |||
| JoinType | jointype, | |||
| SpecialJoinInfo * | sjinfo | |||
| ) |
Definition at line 1713 of file selfuncs.c.
References ScalarArrayOpExpr::args, ARR_ELEMTYPE, Assert, CLAMP_PROBABILITY, CaseTestExpr::collation, DatumGetArrayTypeP, DatumGetFloat8, deconstruct_array(), ArrayExpr::element_typeid, ArrayExpr::elements, TypeCacheEntry::eq_opr, exprCollation(), exprType(), fmgr_info(), FunctionCall4Coll(), FunctionCall5Coll(), get_base_element_type(), get_negator(), get_oprjoin(), get_oprrest(), get_typlenbyval(), get_typlenbyvalalign(), i, ScalarArrayOpExpr::inputcollid, Int16GetDatum, Int32GetDatum, IsA, lfirst, linitial, list_length(), list_make2, lookup_type_cache(), lsecond, makeConst(), makeNode, ObjectIdGetDatum, OidIsValid, ScalarArrayOpExpr::opno, PointerGetDatum, s1, s2, scalararraysel_containment(), strip_array_coercion(), TYPECACHE_EQ_OPR, CaseTestExpr::typeId, CaseTestExpr::typeMod, and ScalarArrayOpExpr::useOr.
Referenced by clause_selectivity().
{
Oid operator = clause->opno;
bool useOr = clause->useOr;
bool isEquality = false;
bool isInequality = false;
Node *leftop;
Node *rightop;
Oid nominal_element_type;
Oid nominal_element_collation;
TypeCacheEntry *typentry;
RegProcedure oprsel;
FmgrInfo oprselproc;
Selectivity s1;
Selectivity s1disjoint;
/* First, deconstruct the expression */
Assert(list_length(clause->args) == 2);
leftop = (Node *) linitial(clause->args);
rightop = (Node *) lsecond(clause->args);
/* get nominal (after relabeling) element type of rightop */
nominal_element_type = get_base_element_type(exprType(rightop));
if (!OidIsValid(nominal_element_type))
return (Selectivity) 0.5; /* probably shouldn't happen */
/* get nominal collation, too, for generating constants */
nominal_element_collation = exprCollation(rightop);
/* look through any binary-compatible relabeling of rightop */
rightop = strip_array_coercion(rightop);
/*
* Detect whether the operator is the default equality or inequality
* operator of the array element type.
*/
typentry = lookup_type_cache(nominal_element_type, TYPECACHE_EQ_OPR);
if (OidIsValid(typentry->eq_opr))
{
if (operator == typentry->eq_opr)
isEquality = true;
else if (get_negator(operator) == typentry->eq_opr)
isInequality = true;
}
/*
* If it is equality or inequality, we might be able to estimate this as a
* form of array containment; for instance "const = ANY(column)" can be
* treated as "ARRAY[const] <@ column". scalararraysel_containment tries
* that, and returns the selectivity estimate if successful, or -1 if not.
*/
if ((isEquality || isInequality) && !is_join_clause)
{
s1 = scalararraysel_containment(root, leftop, rightop,
nominal_element_type,
isEquality, useOr, varRelid);
if (s1 >= 0.0)
return s1;
}
/*
* Look up the underlying operator's selectivity estimator. Punt if it
* hasn't got one.
*/
if (is_join_clause)
oprsel = get_oprjoin(operator);
else
oprsel = get_oprrest(operator);
if (!oprsel)
return (Selectivity) 0.5;
fmgr_info(oprsel, &oprselproc);
/*
* In the array-containment check above, we must only believe that an
* operator is equality or inequality if it is the default btree equality
* operator (or its negator) for the element type, since those are the
* operators that array containment will use. But in what follows, we can
* be a little laxer, and also believe that any operators using eqsel() or
* neqsel() as selectivity estimator act like equality or inequality.
*/
if (oprsel == F_EQSEL || oprsel == F_EQJOINSEL)
isEquality = true;
else if (oprsel == F_NEQSEL || oprsel == F_NEQJOINSEL)
isInequality = true;
/*
* We consider three cases:
*
* 1. rightop is an Array constant: deconstruct the array, apply the
* operator's selectivity function for each array element, and merge the
* results in the same way that clausesel.c does for AND/OR combinations.
*
* 2. rightop is an ARRAY[] construct: apply the operator's selectivity
* function for each element of the ARRAY[] construct, and merge.
*
* 3. otherwise, make a guess ...
*/
if (rightop && IsA(rightop, Const))
{
Datum arraydatum = ((Const *) rightop)->constvalue;
bool arrayisnull = ((Const *) rightop)->constisnull;
ArrayType *arrayval;
int16 elmlen;
bool elmbyval;
char elmalign;
int num_elems;
Datum *elem_values;
bool *elem_nulls;
int i;
if (arrayisnull) /* qual can't succeed if null array */
return (Selectivity) 0.0;
arrayval = DatumGetArrayTypeP(arraydatum);
get_typlenbyvalalign(ARR_ELEMTYPE(arrayval),
&elmlen, &elmbyval, &elmalign);
deconstruct_array(arrayval,
ARR_ELEMTYPE(arrayval),
elmlen, elmbyval, elmalign,
&elem_values, &elem_nulls, &num_elems);
/*
* For generic operators, we assume the probability of success is
* independent for each array element. But for "= ANY" or "<> ALL",
* if the array elements are distinct (which'd typically be the case)
* then the probabilities are disjoint, and we should just sum them.
*
* If we were being really tense we would try to confirm that the
* elements are all distinct, but that would be expensive and it
* doesn't seem to be worth the cycles; it would amount to penalizing
* well-written queries in favor of poorly-written ones. However, we
* do protect ourselves a little bit by checking whether the
* disjointness assumption leads to an impossible (out of range)
* probability; if so, we fall back to the normal calculation.
*/
s1 = s1disjoint = (useOr ? 0.0 : 1.0);
for (i = 0; i < num_elems; i++)
{
List *args;
Selectivity s2;
args = list_make2(leftop,
makeConst(nominal_element_type,
-1,
nominal_element_collation,
elmlen,
elem_values[i],
elem_nulls[i],
elmbyval));
if (is_join_clause)
s2 = DatumGetFloat8(FunctionCall5Coll(&oprselproc,
clause->inputcollid,
PointerGetDatum(root),
ObjectIdGetDatum(operator),
PointerGetDatum(args),
Int16GetDatum(jointype),
PointerGetDatum(sjinfo)));
else
s2 = DatumGetFloat8(FunctionCall4Coll(&oprselproc,
clause->inputcollid,
PointerGetDatum(root),
ObjectIdGetDatum(operator),
PointerGetDatum(args),
Int32GetDatum(varRelid)));
if (useOr)
{
s1 = s1 + s2 - s1 * s2;
if (isEquality)
s1disjoint += s2;
}
else
{
s1 = s1 * s2;
if (isInequality)
s1disjoint += s2 - 1.0;
}
}
/* accept disjoint-probability estimate if in range */
if ((useOr ? isEquality : isInequality) &&
s1disjoint >= 0.0 && s1disjoint <= 1.0)
s1 = s1disjoint;
}
else if (rightop && IsA(rightop, ArrayExpr) &&
!((ArrayExpr *) rightop)->multidims)
{
ArrayExpr *arrayexpr = (ArrayExpr *) rightop;
int16 elmlen;
bool elmbyval;
ListCell *l;
get_typlenbyval(arrayexpr->element_typeid,
&elmlen, &elmbyval);
/*
* We use the assumption of disjoint probabilities here too, although
* the odds of equal array elements are rather higher if the elements
* are not all constants (which they won't be, else constant folding
* would have reduced the ArrayExpr to a Const). In this path it's
* critical to have the sanity check on the s1disjoint estimate.
*/
s1 = s1disjoint = (useOr ? 0.0 : 1.0);
foreach(l, arrayexpr->elements)
{
Node *elem = (Node *) lfirst(l);
List *args;
Selectivity s2;
/*
* Theoretically, if elem isn't of nominal_element_type we should
* insert a RelabelType, but it seems unlikely that any operator
* estimation function would really care ...
*/
args = list_make2(leftop, elem);
if (is_join_clause)
s2 = DatumGetFloat8(FunctionCall5Coll(&oprselproc,
clause->inputcollid,
PointerGetDatum(root),
ObjectIdGetDatum(operator),
PointerGetDatum(args),
Int16GetDatum(jointype),
PointerGetDatum(sjinfo)));
else
s2 = DatumGetFloat8(FunctionCall4Coll(&oprselproc,
clause->inputcollid,
PointerGetDatum(root),
ObjectIdGetDatum(operator),
PointerGetDatum(args),
Int32GetDatum(varRelid)));
if (useOr)
{
s1 = s1 + s2 - s1 * s2;
if (isEquality)
s1disjoint += s2;
}
else
{
s1 = s1 * s2;
if (isInequality)
s1disjoint += s2 - 1.0;
}
}
/* accept disjoint-probability estimate if in range */
if ((useOr ? isEquality : isInequality) &&
s1disjoint >= 0.0 && s1disjoint <= 1.0)
s1 = s1disjoint;
}
else
{
CaseTestExpr *dummyexpr;
List *args;
Selectivity s2;
int i;
/*
* We need a dummy rightop to pass to the operator selectivity
* routine. It can be pretty much anything that doesn't look like a
* constant; CaseTestExpr is a convenient choice.
*/
dummyexpr = makeNode(CaseTestExpr);
dummyexpr->typeId = nominal_element_type;
dummyexpr->typeMod = -1;
dummyexpr->collation = clause->inputcollid;
args = list_make2(leftop, dummyexpr);
if (is_join_clause)
s2 = DatumGetFloat8(FunctionCall5Coll(&oprselproc,
clause->inputcollid,
PointerGetDatum(root),
ObjectIdGetDatum(operator),
PointerGetDatum(args),
Int16GetDatum(jointype),
PointerGetDatum(sjinfo)));
else
s2 = DatumGetFloat8(FunctionCall4Coll(&oprselproc,
clause->inputcollid,
PointerGetDatum(root),
ObjectIdGetDatum(operator),
PointerGetDatum(args),
Int32GetDatum(varRelid)));
s1 = useOr ? 0.0 : 1.0;
/*
* Arbitrarily assume 10 elements in the eventual array value (see
* also estimate_array_length). We don't risk an assumption of
* disjoint probabilities here.
*/
for (i = 0; i < 10; i++)
{
if (useOr)
s1 = s1 + s2 - s1 * s2;
else
s1 = s1 * s2;
}
}
/* result should be in range, but make sure... */
CLAMP_PROBABILITY(s1);
return s1;
}
| Datum scalargtjoinsel | ( | PG_FUNCTION_ARGS | ) |
Definition at line 2675 of file selfuncs.c.
References DEFAULT_INEQ_SEL, and PG_RETURN_FLOAT8.
| Datum scalargtsel | ( | PG_FUNCTION_ARGS | ) |
Definition at line 1034 of file selfuncs.c.
References DEFAULT_INEQ_SEL, get_restriction_variable(), IsA, PG_GETARG_INT32, PG_GETARG_POINTER, PG_RETURN_FLOAT8, ReleaseVariableStats, and scalarineqsel().
{
PlannerInfo *root = (PlannerInfo *) PG_GETARG_POINTER(0);
Oid operator = PG_GETARG_OID(1);
List *args = (List *) PG_GETARG_POINTER(2);
int varRelid = PG_GETARG_INT32(3);
VariableStatData vardata;
Node *other;
bool varonleft;
Datum constval;
Oid consttype;
bool isgt;
double selec;
/*
* If expression is not variable op something or something op variable,
* then punt and return a default estimate.
*/
if (!get_restriction_variable(root, args, varRelid,
&vardata, &other, &varonleft))
PG_RETURN_FLOAT8(DEFAULT_INEQ_SEL);
/*
* Can't do anything useful if the something is not a constant, either.
*/
if (!IsA(other, Const))
{
ReleaseVariableStats(vardata);
PG_RETURN_FLOAT8(DEFAULT_INEQ_SEL);
}
/*
* If the constant is NULL, assume operator is strict and return zero, ie,
* operator will never return TRUE.
*/
if (((Const *) other)->constisnull)
{
ReleaseVariableStats(vardata);
PG_RETURN_FLOAT8(0.0);
}
constval = ((Const *) other)->constvalue;
consttype = ((Const *) other)->consttype;
/*
* Force the var to be on the left to simplify logic in scalarineqsel.
*/
if (varonleft)
{
/* we have var > other */
isgt = true;
}
else
{
/* we have other > var, commute to make var < other */
operator = get_commutator(operator);
if (!operator)
{
/* Use default selectivity (should we raise an error instead?) */
ReleaseVariableStats(vardata);
PG_RETURN_FLOAT8(DEFAULT_INEQ_SEL);
}
isgt = false;
}
selec = scalarineqsel(root, operator, isgt, &vardata, constval, consttype);
ReleaseVariableStats(vardata);
PG_RETURN_FLOAT8((float8) selec);
}
| static double scalarineqsel | ( | PlannerInfo * | root, | |
| Oid | operator, | |||
| bool | isgt, | |||
| VariableStatData * | vardata, | |||
| Datum | constval, | |||
| Oid | consttype | |||
| ) | [static] |
Definition at line 528 of file selfuncs.c.
References CLAMP_PROBABILITY, fmgr_info(), get_opcode(), GETSTRUCT, HeapTupleIsValid, ineq_histogram_selectivity(), mcv_selectivity(), and VariableStatData::statsTuple.
Referenced by mergejoinscansel(), scalargtsel(), and scalarltsel().
{
Form_pg_statistic stats;
FmgrInfo opproc;
double mcv_selec,
hist_selec,
sumcommon;
double selec;
if (!HeapTupleIsValid(vardata->statsTuple))
{
/* no stats available, so default result */
return DEFAULT_INEQ_SEL;
}
stats = (Form_pg_statistic) GETSTRUCT(vardata->statsTuple);
fmgr_info(get_opcode(operator), &opproc);
/*
* If we have most-common-values info, add up the fractions of the MCV
* entries that satisfy MCV OP CONST. These fractions contribute directly
* to the result selectivity. Also add up the total fraction represented
* by MCV entries.
*/
mcv_selec = mcv_selectivity(vardata, &opproc, constval, true,
&sumcommon);
/*
* If there is a histogram, determine which bin the constant falls in, and
* compute the resulting contribution to selectivity.
*/
hist_selec = ineq_histogram_selectivity(root, vardata, &opproc, isgt,
constval, consttype);
/*
* Now merge the results from the MCV and histogram calculations,
* realizing that the histogram covers only the non-null values that are
* not listed in MCV.
*/
selec = 1.0 - stats->stanullfrac - sumcommon;
if (hist_selec >= 0.0)
selec *= hist_selec;
else
{
/*
* If no histogram but there are values not accounted for by MCV,
* arbitrarily assume half of them will match.
*/
selec *= 0.5;
}
selec += mcv_selec;
/* result should be in range, but make sure... */
CLAMP_PROBABILITY(selec);
return selec;
}
| Datum scalarltjoinsel | ( | PG_FUNCTION_ARGS | ) |
Definition at line 2666 of file selfuncs.c.
References DEFAULT_INEQ_SEL, and PG_RETURN_FLOAT8.
| Datum scalarltsel | ( | PG_FUNCTION_ARGS | ) |
Definition at line 959 of file selfuncs.c.
References DEFAULT_INEQ_SEL, get_restriction_variable(), IsA, PG_GETARG_INT32, PG_GETARG_POINTER, PG_RETURN_FLOAT8, ReleaseVariableStats, and scalarineqsel().
{
PlannerInfo *root = (PlannerInfo *) PG_GETARG_POINTER(0);
Oid operator = PG_GETARG_OID(1);
List *args = (List *) PG_GETARG_POINTER(2);
int varRelid = PG_GETARG_INT32(3);
VariableStatData vardata;
Node *other;
bool varonleft;
Datum constval;
Oid consttype;
bool isgt;
double selec;
/*
* If expression is not variable op something or something op variable,
* then punt and return a default estimate.
*/
if (!get_restriction_variable(root, args, varRelid,
&vardata, &other, &varonleft))
PG_RETURN_FLOAT8(DEFAULT_INEQ_SEL);
/*
* Can't do anything useful if the something is not a constant, either.
*/
if (!IsA(other, Const))
{
ReleaseVariableStats(vardata);
PG_RETURN_FLOAT8(DEFAULT_INEQ_SEL);
}
/*
* If the constant is NULL, assume operator is strict and return zero, ie,
* operator will never return TRUE.
*/
if (((Const *) other)->constisnull)
{
ReleaseVariableStats(vardata);
PG_RETURN_FLOAT8(0.0);
}
constval = ((Const *) other)->constvalue;
consttype = ((Const *) other)->consttype;
/*
* Force the var to be on the left to simplify logic in scalarineqsel.
*/
if (varonleft)
{
/* we have var < other */
isgt = false;
}
else
{
/* we have other < var, commute to make var > other */
operator = get_commutator(operator);
if (!operator)
{
/* Use default selectivity (should we raise an error instead?) */
ReleaseVariableStats(vardata);
PG_RETURN_FLOAT8(DEFAULT_INEQ_SEL);
}
isgt = true;
}
selec = scalarineqsel(root, operator, isgt, &vardata, constval, consttype);
ReleaseVariableStats(vardata);
PG_RETURN_FLOAT8((float8) selec);
}
| Datum spgcostestimate | ( | PG_FUNCTION_ARGS | ) |
Definition at line 6648 of file selfuncs.c.
References cpu_operator_cost, genericcostestimate(), GenericCosts::indexCorrelation, IndexPath::indexinfo, GenericCosts::indexSelectivity, GenericCosts::indexStartupCost, GenericCosts::indexTotalCost, MemSet, GenericCosts::num_sa_scans, IndexOptInfo::pages, PG_GETARG_FLOAT8, PG_GETARG_POINTER, PG_RETURN_VOID, IndexOptInfo::tree_height, and IndexOptInfo::tuples.
{
PlannerInfo *root = (PlannerInfo *) PG_GETARG_POINTER(0);
IndexPath *path = (IndexPath *) PG_GETARG_POINTER(1);
double loop_count = PG_GETARG_FLOAT8(2);
Cost *indexStartupCost = (Cost *) PG_GETARG_POINTER(3);
Cost *indexTotalCost = (Cost *) PG_GETARG_POINTER(4);
Selectivity *indexSelectivity = (Selectivity *) PG_GETARG_POINTER(5);
double *indexCorrelation = (double *) PG_GETARG_POINTER(6);
IndexOptInfo *index = path->indexinfo;
GenericCosts costs;
Cost descentCost;
MemSet(&costs, 0, sizeof(costs));
genericcostestimate(root, path, loop_count, &costs);
/*
* We model index descent costs similarly to those for btree, but to do
* that we first need an idea of the tree height. We somewhat arbitrarily
* assume that the fanout is 100, meaning the tree height is at most
* log100(index->pages).
*
* Although this computation isn't really expensive enough to require
* caching, we might as well use index->tree_height to cache it.
*/
if (index->tree_height < 0) /* unknown? */
{
if (index->pages > 1) /* avoid computing log(0) */
index->tree_height = (int) (log(index->pages) / log(100.0));
else
index->tree_height = 0;
}
/*
* Add a CPU-cost component to represent the costs of initial descent.
* We just use log(N) here not log2(N) since the branching factor isn't
* necessarily two anyway. As for btree, charge once per SA scan.
*/
if (index->tuples > 1) /* avoid computing log(0) */
{
descentCost = ceil(log(index->tuples)) * cpu_operator_cost;
costs.indexStartupCost += descentCost;
costs.indexTotalCost += costs.num_sa_scans * descentCost;
}
/*
* Likewise add a per-page charge, calculated the same as for btrees.
*/
descentCost = (index->tree_height + 1) * 50.0 * cpu_operator_cost;
costs.indexStartupCost += descentCost;
costs.indexTotalCost += costs.num_sa_scans * descentCost;
*indexStartupCost = costs.indexStartupCost;
*indexTotalCost = costs.indexTotalCost;
*indexSelectivity = costs.indexSelectivity;
*indexCorrelation = costs.indexCorrelation;
PG_RETURN_VOID();
}
| static Const * string_to_bytea_const | ( | const char * | str, | |
| size_t | str_len | |||
| ) | [static] |
Definition at line 5900 of file selfuncs.c.
References BYTEAOID, InvalidOid, makeConst(), palloc(), PointerGetDatum, SET_VARSIZE, VARDATA, and VARHDRSZ.
Referenced by like_fixed_prefix(), and make_greater_string().
{
bytea *bstr = palloc(VARHDRSZ + str_len);
Datum conval;
memcpy(VARDATA(bstr), str, str_len);
SET_VARSIZE(bstr, VARHDRSZ + str_len);
conval = PointerGetDatum(bstr);
return makeConst(BYTEAOID, -1, InvalidOid, -1, conval, false, false);
}
Definition at line 5857 of file selfuncs.c.
References BPCHAROID, BYTEAOID, elog, ERROR, makeConst(), NAMEOID, string_to_datum(), TEXTOID, and VARCHAROID.
Referenced by like_fixed_prefix(), make_greater_string(), patternsel(), and regex_fixed_prefix().
{
Datum conval = string_to_datum(str, datatype);
Oid collation;
int constlen;
/*
* We only need to support a few datatypes here, so hard-wire properties
* instead of incurring the expense of catalog lookups.
*/
switch (datatype)
{
case TEXTOID:
case VARCHAROID:
case BPCHAROID:
collation = DEFAULT_COLLATION_OID;
constlen = -1;
break;
case NAMEOID:
collation = InvalidOid;
constlen = NAMEDATALEN;
break;
case BYTEAOID:
collation = InvalidOid;
constlen = -1;
break;
default:
elog(ERROR, "unexpected datatype in string_to_const: %u",
datatype);
return NULL;
}
return makeConst(datatype, -1, collation, constlen,
conval, false, false);
}
Definition at line 5837 of file selfuncs.c.
References Assert, byteain(), BYTEAOID, CStringGetDatum, CStringGetTextDatum, DirectFunctionCall1, namein(), NAMEOID, and NULL.
Referenced by string_to_const().
{
Assert(str != NULL);
/*
* We cheat a little by assuming that CStringGetTextDatum() will do for
* bpchar and varchar constants too...
*/
if (datatype == NAMEOID)
return DirectFunctionCall1(namein, CStringGetDatum(str));
else if (datatype == BYTEAOID)
return DirectFunctionCall1(byteain, CStringGetDatum(str));
else
return CStringGetTextDatum(str);
}
Definition at line 1689 of file selfuncs.c.
References arg, InvalidOid, and IsA.
Referenced by estimate_array_length(), and scalararraysel().
{
for (;;)
{
if (node && IsA(node, ArrayCoerceExpr) &&
((ArrayCoerceExpr *) node)->elemfuncid == InvalidOid)
{
node = (Node *) ((ArrayCoerceExpr *) node)->arg;
}
else if (node && IsA(node, RelabelType))
{
/* We don't really expect this case, but may as well cope */
node = (Node *) ((RelabelType *) node)->arg;
}
else
break;
}
return node;
}
| static double var_eq_const | ( | VariableStatData * | vardata, | |
| Oid | operator, | |||
| Datum | constval, | |||
| bool | constisnull, | |||
| bool | varonleft | |||
| ) | [static] |
Definition at line 260 of file selfuncs.c.
References VariableStatData::atttype, VariableStatData::atttypmod, CLAMP_PROBABILITY, DatumGetBool, DEFAULT_COLLATION_OID, fmgr_info(), free_attstatsslot(), FunctionCall2Coll(), get_attstatsslot(), get_opcode(), get_variable_numdistinct(), GETSTRUCT, HeapTupleIsValid, i, InvalidOid, VariableStatData::isunique, NULL, VariableStatData::rel, STATISTIC_KIND_MCV, VariableStatData::statsTuple, RelOptInfo::tuples, and values.
Referenced by eqsel(), patternsel(), and prefix_selectivity().
{
double selec;
bool isdefault;
/*
* If the constant is NULL, assume operator is strict and return zero, ie,
* operator will never return TRUE.
*/
if (constisnull)
return 0.0;
/*
* If we matched the var to a unique index or DISTINCT clause, assume
* there is exactly one match regardless of anything else. (This is
* slightly bogus, since the index or clause's equality operator might be
* different from ours, but it's much more likely to be right than
* ignoring the information.)
*/
if (vardata->isunique && vardata->rel && vardata->rel->tuples >= 1.0)
return 1.0 / vardata->rel->tuples;
if (HeapTupleIsValid(vardata->statsTuple))
{
Form_pg_statistic stats;
Datum *values;
int nvalues;
float4 *numbers;
int nnumbers;
bool match = false;
int i;
stats = (Form_pg_statistic) GETSTRUCT(vardata->statsTuple);
/*
* Is the constant "=" to any of the column's most common values?
* (Although the given operator may not really be "=", we will assume
* that seeing whether it returns TRUE is an appropriate test. If you
* don't like this, maybe you shouldn't be using eqsel for your
* operator...)
*/
if (get_attstatsslot(vardata->statsTuple,
vardata->atttype, vardata->atttypmod,
STATISTIC_KIND_MCV, InvalidOid,
NULL,
&values, &nvalues,
&numbers, &nnumbers))
{
FmgrInfo eqproc;
fmgr_info(get_opcode(operator), &eqproc);
for (i = 0; i < nvalues; i++)
{
/* be careful to apply operator right way 'round */
if (varonleft)
match = DatumGetBool(FunctionCall2Coll(&eqproc,
DEFAULT_COLLATION_OID,
values[i],
constval));
else
match = DatumGetBool(FunctionCall2Coll(&eqproc,
DEFAULT_COLLATION_OID,
constval,
values[i]));
if (match)
break;
}
}
else
{
/* no most-common-value info available */
values = NULL;
numbers = NULL;
i = nvalues = nnumbers = 0;
}
if (match)
{
/*
* Constant is "=" to this common value. We know selectivity
* exactly (or as exactly as ANALYZE could calculate it, anyway).
*/
selec = numbers[i];
}
else
{
/*
* Comparison is against a constant that is neither NULL nor any
* of the common values. Its selectivity cannot be more than
* this:
*/
double sumcommon = 0.0;
double otherdistinct;
for (i = 0; i < nnumbers; i++)
sumcommon += numbers[i];
selec = 1.0 - sumcommon - stats->stanullfrac;
CLAMP_PROBABILITY(selec);
/*
* and in fact it's probably a good deal less. We approximate that
* all the not-common values share this remaining fraction
* equally, so we divide by the number of other distinct values.
*/
otherdistinct = get_variable_numdistinct(vardata, &isdefault) - nnumbers;
if (otherdistinct > 1)
selec /= otherdistinct;
/*
* Another cross-check: selectivity shouldn't be estimated as more
* than the least common "most common value".
*/
if (nnumbers > 0 && selec > numbers[nnumbers - 1])
selec = numbers[nnumbers - 1];
}
free_attstatsslot(vardata->atttype, values, nvalues,
numbers, nnumbers);
}
else
{
/*
* No ANALYZE stats available, so make a guess using estimated number
* of distinct values and assuming they are equally common. (The guess
* is unlikely to be very good, but we do know a few special cases.)
*/
selec = 1.0 / get_variable_numdistinct(vardata, &isdefault);
}
/* result should be in range, but make sure... */
CLAMP_PROBABILITY(selec);
return selec;
}
| static double var_eq_non_const | ( | VariableStatData * | vardata, | |
| Oid | operator, | |||
| Node * | other, | |||
| bool | varonleft | |||
| ) | [static] |
Definition at line 402 of file selfuncs.c.
References VariableStatData::atttype, VariableStatData::atttypmod, CLAMP_PROBABILITY, free_attstatsslot(), get_attstatsslot(), get_variable_numdistinct(), GETSTRUCT, HeapTupleIsValid, InvalidOid, VariableStatData::isunique, NULL, VariableStatData::rel, STATISTIC_KIND_MCV, VariableStatData::statsTuple, and RelOptInfo::tuples.
Referenced by eqsel().
{
double selec;
bool isdefault;
/*
* If we matched the var to a unique index or DISTINCT clause, assume
* there is exactly one match regardless of anything else. (This is
* slightly bogus, since the index or clause's equality operator might be
* different from ours, but it's much more likely to be right than
* ignoring the information.)
*/
if (vardata->isunique && vardata->rel && vardata->rel->tuples >= 1.0)
return 1.0 / vardata->rel->tuples;
if (HeapTupleIsValid(vardata->statsTuple))
{
Form_pg_statistic stats;
double ndistinct;
float4 *numbers;
int nnumbers;
stats = (Form_pg_statistic) GETSTRUCT(vardata->statsTuple);
/*
* Search is for a value that we do not know a priori, but we will
* assume it is not NULL. Estimate the selectivity as non-null
* fraction divided by number of distinct values, so that we get a
* result averaged over all possible values whether common or
* uncommon. (Essentially, we are assuming that the not-yet-known
* comparison value is equally likely to be any of the possible
* values, regardless of their frequency in the table. Is that a good
* idea?)
*/
selec = 1.0 - stats->stanullfrac;
ndistinct = get_variable_numdistinct(vardata, &isdefault);
if (ndistinct > 1)
selec /= ndistinct;
/*
* Cross-check: selectivity should never be estimated as more than the
* most common value's.
*/
if (get_attstatsslot(vardata->statsTuple,
vardata->atttype, vardata->atttypmod,
STATISTIC_KIND_MCV, InvalidOid,
NULL,
NULL, NULL,
&numbers, &nnumbers))
{
if (nnumbers > 0 && selec > numbers[0])
selec = numbers[0];
free_attstatsslot(vardata->atttype, NULL, 0, numbers, nnumbers);
}
}
else
{
/*
* No ANALYZE stats available, so make a guess using estimated number
* of distinct values and assuming they are equally common. (The guess
* is unlikely to be very good, but we do know a few special cases.)
*/
selec = 1.0 / get_variable_numdistinct(vardata, &isdefault);
}
/* result should be in range, but make sure... */
CLAMP_PROBABILITY(selec);
return selec;
}
Definition at line 145 of file selfuncs.c.
Referenced by btcostestimate(), and examine_variable().
Definition at line 144 of file selfuncs.c.
Referenced by btcostestimate(), and examine_simple_variable().
1.7.1