Header And Logo
|
#include "nodes/relation.h"#include "utils/relcache.h"
Go to the source code of this file.
Typedefs | |
| typedef void(* | get_relation_info_hook_type )(PlannerInfo *root, Oid relationObjectId, bool inhparent, RelOptInfo *rel) |
Functions | |
| void | get_relation_info (PlannerInfo *root, Oid relationObjectId, bool inhparent, RelOptInfo *rel) |
| void | estimate_rel_size (Relation rel, int32 *attr_widths, BlockNumber *pages, double *tuples, double *allvisfrac) |
| int32 | get_relation_data_width (Oid relid, int32 *attr_widths) |
| bool | relation_excluded_by_constraints (PlannerInfo *root, RelOptInfo *rel, RangeTblEntry *rte) |
| List * | build_physical_tlist (PlannerInfo *root, RelOptInfo *rel) |
| bool | has_unique_index (RelOptInfo *rel, AttrNumber attno) |
| Selectivity | restriction_selectivity (PlannerInfo *root, Oid operatorid, List *args, Oid inputcollid, int varRelid) |
| Selectivity | join_selectivity (PlannerInfo *root, Oid operatorid, List *args, Oid inputcollid, JoinType jointype, SpecialJoinInfo *sjinfo) |
Variables | |
| PGDLLIMPORT get_relation_info_hook_type | get_relation_info_hook |
| typedef void(* get_relation_info_hook_type)(PlannerInfo *root, Oid relationObjectId, bool inhparent, RelOptInfo *rel) |
| List* build_physical_tlist | ( | PlannerInfo * | root, | |
| RelOptInfo * | rel | |||
| ) |
Definition at line 848 of file plancat.c.
References tupleDesc::attrs, elog, ERROR, expandRTE(), heap_close, heap_open(), IsA, lappend(), lfirst, makeTargetEntry(), makeVar(), makeVarFromTargetEntry(), NoLock, NULL, planner_rt_fetch, RelationData::rd_att, RelationGetNumberOfAttributes, RangeTblEntry::relid, RelOptInfo::relid, TargetEntry::resjunk, TargetEntry::resno, RTE_CTE, RTE_FUNCTION, RTE_RELATION, RTE_SUBQUERY, RTE_VALUES, RangeTblEntry::rtekind, RangeTblEntry::subquery, and Query::targetList.
Referenced by create_scan_plan().
{
List *tlist = NIL;
Index varno = rel->relid;
RangeTblEntry *rte = planner_rt_fetch(varno, root);
Relation relation;
Query *subquery;
Var *var;
ListCell *l;
int attrno,
numattrs;
List *colvars;
switch (rte->rtekind)
{
case RTE_RELATION:
/* Assume we already have adequate lock */
relation = heap_open(rte->relid, NoLock);
numattrs = RelationGetNumberOfAttributes(relation);
for (attrno = 1; attrno <= numattrs; attrno++)
{
Form_pg_attribute att_tup = relation->rd_att->attrs[attrno - 1];
if (att_tup->attisdropped)
{
/* found a dropped col, so punt */
tlist = NIL;
break;
}
var = makeVar(varno,
attrno,
att_tup->atttypid,
att_tup->atttypmod,
att_tup->attcollation,
0);
tlist = lappend(tlist,
makeTargetEntry((Expr *) var,
attrno,
NULL,
false));
}
heap_close(relation, NoLock);
break;
case RTE_SUBQUERY:
subquery = rte->subquery;
foreach(l, subquery->targetList)
{
TargetEntry *tle = (TargetEntry *) lfirst(l);
/*
* A resjunk column of the subquery can be reflected as
* resjunk in the physical tlist; we need not punt.
*/
var = makeVarFromTargetEntry(varno, tle);
tlist = lappend(tlist,
makeTargetEntry((Expr *) var,
tle->resno,
NULL,
tle->resjunk));
}
break;
case RTE_FUNCTION:
case RTE_VALUES:
case RTE_CTE:
/* Not all of these can have dropped cols, but share code anyway */
expandRTE(rte, varno, 0, -1, true /* include dropped */ ,
NULL, &colvars);
foreach(l, colvars)
{
var = (Var *) lfirst(l);
/*
* A non-Var in expandRTE's output means a dropped column;
* must punt.
*/
if (!IsA(var, Var))
{
tlist = NIL;
break;
}
tlist = lappend(tlist,
makeTargetEntry((Expr *) var,
var->varattno,
NULL,
false));
}
break;
default:
/* caller error */
elog(ERROR, "unsupported RTE kind %d in build_physical_tlist",
(int) rte->rtekind);
break;
}
return tlist;
}
| void estimate_rel_size | ( | Relation | rel, | |
| int32 * | attr_widths, | |||
| BlockNumber * | pages, | |||
| double * | tuples, | |||
| double * | allvisfrac | |||
| ) |
Definition at line 407 of file plancat.c.
References get_rel_data_width(), RelationData::rd_rel, RelationGetNumberOfBlocks, RELKIND_FOREIGN_TABLE, RELKIND_INDEX, RELKIND_MATVIEW, RELKIND_RELATION, RELKIND_SEQUENCE, RELKIND_TOASTVALUE, and rint().
Referenced by get_relation_info(), and hashbuild().
{
BlockNumber curpages;
BlockNumber relpages;
double reltuples;
BlockNumber relallvisible;
double density;
switch (rel->rd_rel->relkind)
{
case RELKIND_RELATION:
case RELKIND_INDEX:
case RELKIND_MATVIEW:
case RELKIND_TOASTVALUE:
/* it has storage, ok to call the smgr */
curpages = RelationGetNumberOfBlocks(rel);
/*
* HACK: if the relation has never yet been vacuumed, use a
* minimum size estimate of 10 pages. The idea here is to avoid
* assuming a newly-created table is really small, even if it
* currently is, because that may not be true once some data gets
* loaded into it. Once a vacuum or analyze cycle has been done
* on it, it's more reasonable to believe the size is somewhat
* stable.
*
* (Note that this is only an issue if the plan gets cached and
* used again after the table has been filled. What we're trying
* to avoid is using a nestloop-type plan on a table that has
* grown substantially since the plan was made. Normally,
* autovacuum/autoanalyze will occur once enough inserts have
* happened and cause cached-plan invalidation; but that doesn't
* happen instantaneously, and it won't happen at all for cases
* such as temporary tables.)
*
* We approximate "never vacuumed" by "has relpages = 0", which
* means this will also fire on genuinely empty relations. Not
* great, but fortunately that's a seldom-seen case in the real
* world, and it shouldn't degrade the quality of the plan too
* much anyway to err in this direction.
*
* There are two exceptions wherein we don't apply this heuristic.
* One is if the table has inheritance children. Totally empty
* parent tables are quite common, so we should be willing to
* believe that they are empty. Also, we don't apply the 10-page
* minimum to indexes.
*/
if (curpages < 10 &&
rel->rd_rel->relpages == 0 &&
!rel->rd_rel->relhassubclass &&
rel->rd_rel->relkind != RELKIND_INDEX)
curpages = 10;
/* report estimated # pages */
*pages = curpages;
/* quick exit if rel is clearly empty */
if (curpages == 0)
{
*tuples = 0;
*allvisfrac = 0;
break;
}
/* coerce values in pg_class to more desirable types */
relpages = (BlockNumber) rel->rd_rel->relpages;
reltuples = (double) rel->rd_rel->reltuples;
relallvisible = (BlockNumber) rel->rd_rel->relallvisible;
/*
* If it's an index, discount the metapage while estimating the
* number of tuples. This is a kluge because it assumes more than
* it ought to about index structure. Currently it's OK for
* btree, hash, and GIN indexes but suspect for GiST indexes.
*/
if (rel->rd_rel->relkind == RELKIND_INDEX &&
relpages > 0)
{
curpages--;
relpages--;
}
/* estimate number of tuples from previous tuple density */
if (relpages > 0)
density = reltuples / (double) relpages;
else
{
/*
* When we have no data because the relation was truncated,
* estimate tuple width from attribute datatypes. We assume
* here that the pages are completely full, which is OK for
* tables (since they've presumably not been VACUUMed yet) but
* is probably an overestimate for indexes. Fortunately
* get_relation_info() can clamp the overestimate to the
* parent table's size.
*
* Note: this code intentionally disregards alignment
* considerations, because (a) that would be gilding the lily
* considering how crude the estimate is, and (b) it creates
* platform dependencies in the default plans which are kind
* of a headache for regression testing.
*/
int32 tuple_width;
tuple_width = get_rel_data_width(rel, attr_widths);
tuple_width += sizeof(HeapTupleHeaderData);
tuple_width += sizeof(ItemPointerData);
/* note: integer division is intentional here */
density = (BLCKSZ - SizeOfPageHeaderData) / tuple_width;
}
*tuples = rint(density * (double) curpages);
/*
* We use relallvisible as-is, rather than scaling it up like we
* do for the pages and tuples counts, on the theory that any
* pages added since the last VACUUM are most likely not marked
* all-visible. But costsize.c wants it converted to a fraction.
*/
if (relallvisible == 0 || curpages <= 0)
*allvisfrac = 0;
else if ((double) relallvisible >= curpages)
*allvisfrac = 1;
else
*allvisfrac = (double) relallvisible / curpages;
break;
case RELKIND_SEQUENCE:
/* Sequences always have a known size */
*pages = 1;
*tuples = 1;
*allvisfrac = 0;
break;
case RELKIND_FOREIGN_TABLE:
/* Just use whatever's in pg_class */
*pages = rel->rd_rel->relpages;
*tuples = rel->rd_rel->reltuples;
*allvisfrac = 0;
break;
default:
/* else it has no disk storage; probably shouldn't get here? */
*pages = 0;
*tuples = 0;
*allvisfrac = 0;
break;
}
}
Definition at line 609 of file plancat.c.
References get_rel_data_width(), heap_close, heap_open(), and NoLock.
Referenced by plan_cluster_use_sort(), and set_rel_width().
{
int32 result;
Relation relation;
/* As above, assume relation is already locked */
relation = heap_open(relid, NoLock);
result = get_rel_data_width(relation, attr_widths);
heap_close(relation, NoLock);
return result;
}
| void get_relation_info | ( | PlannerInfo * | root, | |
| Oid | relationObjectId, | |||
| bool | inhparent, | |||
| RelOptInfo * | rel | |||
| ) |
Definition at line 85 of file plancat.c.
References _bt_getrootheight(), RelOptInfo::allvisfrac, IndexOptInfo::amcanorderbyop, IndexOptInfo::amcostestimate, IndexOptInfo::amhasgetbitmap, IndexOptInfo::amhasgettuple, IndexOptInfo::amoptionalkey, IndexOptInfo::amsearcharray, IndexOptInfo::amsearchnulls, Assert, RelOptInfo::attr_needed, RelOptInfo::attr_widths, BTLessStrategyNumber, BTREE_AM_OID, build_index_tlist(), IndexOptInfo::canreturn, ChangeVarNodes(), ereport, errcode(), errmsg(), ERROR, estimate_rel_size(), RelOptInfo::fdwroutine, FirstLowInvalidHeapAttributeNumber, get_opfamily_member(), get_ordering_op_properties(), get_relation_info_hook, GetFdwRoutineForRelation(), PlannerInfo::glob, heap_close, heap_open(), HeapTupleHeaderGetXmin, IndexOptInfo::hypothetical, i, IgnoreSystemIndexes, IndexOptInfo::immediate, index_can_return(), index_close(), index_open(), IndexOptInfo::indexcollations, IndexIsValid, IndexOptInfo::indexkeys, RelOptInfo::indexlist, IndexOptInfo::indexoid, IndexOptInfo::indexprs, IndexOptInfo::indextlist, IndexOptInfo::indpred, IsSystemClass(), lcons(), lfirst_oid, list_free(), makeNode, RelOptInfo::max_attr, RelOptInfo::min_attr, IndexOptInfo::ncolumns, NIL, NoLock, NULL, IndexOptInfo::nulls_first, OidIsValid, IndexOptInfo::opcintype, IndexOptInfo::opfamily, IndexOptInfo::pages, RelOptInfo::pages, palloc(), palloc0(), PlannerInfo::parse, IndexOptInfo::predOK, RelationData::rd_am, RelationData::rd_indcollation, RelationData::rd_index, RelationData::rd_indextuple, RelationData::rd_indoption, RelationData::rd_opcintype, RelationData::rd_opfamily, RelationData::rd_rel, RecoveryInProgress(), IndexOptInfo::rel, IndexOptInfo::relam, RelationGetForm, RelationGetIndexExpressions(), RelationGetIndexList(), RelationGetIndexPredicate(), RelationGetNumberOfAttributes, RelationGetNumberOfBlocks, RelationNeedsWAL, RelOptInfo::relid, RELKIND_FOREIGN_TABLE, IndexOptInfo::reltablespace, RelOptInfo::reltablespace, Query::resultRelation, IndexOptInfo::reverse_sort, IndexOptInfo::sortopfamily, HeapTupleData::t_data, TransactionIdPrecedes(), TransactionXmin, PlannerGlobal::transientPlan, IndexOptInfo::tree_height, IndexOptInfo::tuples, RelOptInfo::tuples, and IndexOptInfo::unique.
Referenced by build_simple_rel().
{
Index varno = rel->relid;
Relation relation;
bool hasindex;
List *indexinfos = NIL;
/*
* We need not lock the relation since it was already locked, either by
* the rewriter or when expand_inherited_rtentry() added it to the query's
* rangetable.
*/
relation = heap_open(relationObjectId, NoLock);
/* Temporary and unlogged relations are inaccessible during recovery. */
if (!RelationNeedsWAL(relation) && RecoveryInProgress())
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("cannot access temporary or unlogged relations during recovery")));
rel->min_attr = FirstLowInvalidHeapAttributeNumber + 1;
rel->max_attr = RelationGetNumberOfAttributes(relation);
rel->reltablespace = RelationGetForm(relation)->reltablespace;
Assert(rel->max_attr >= rel->min_attr);
rel->attr_needed = (Relids *)
palloc0((rel->max_attr - rel->min_attr + 1) * sizeof(Relids));
rel->attr_widths = (int32 *)
palloc0((rel->max_attr - rel->min_attr + 1) * sizeof(int32));
/*
* Estimate relation size --- unless it's an inheritance parent, in which
* case the size will be computed later in set_append_rel_pathlist, and we
* must leave it zero for now to avoid bollixing the total_table_pages
* calculation.
*/
if (!inhparent)
estimate_rel_size(relation, rel->attr_widths - rel->min_attr,
&rel->pages, &rel->tuples, &rel->allvisfrac);
/*
* Make list of indexes. Ignore indexes on system catalogs if told to.
* Don't bother with indexes for an inheritance parent, either.
*/
if (inhparent ||
(IgnoreSystemIndexes && IsSystemClass(relation->rd_rel)))
hasindex = false;
else
hasindex = relation->rd_rel->relhasindex;
if (hasindex)
{
List *indexoidlist;
ListCell *l;
LOCKMODE lmode;
indexoidlist = RelationGetIndexList(relation);
/*
* For each index, we get the same type of lock that the executor will
* need, and do not release it. This saves a couple of trips to the
* shared lock manager while not creating any real loss of
* concurrency, because no schema changes could be happening on the
* index while we hold lock on the parent rel, and neither lock type
* blocks any other kind of index operation.
*/
if (rel->relid == root->parse->resultRelation)
lmode = RowExclusiveLock;
else
lmode = AccessShareLock;
foreach(l, indexoidlist)
{
Oid indexoid = lfirst_oid(l);
Relation indexRelation;
Form_pg_index index;
IndexOptInfo *info;
int ncolumns;
int i;
/*
* Extract info from the relation descriptor for the index.
*/
indexRelation = index_open(indexoid, lmode);
index = indexRelation->rd_index;
/*
* Ignore invalid indexes, since they can't safely be used for
* queries. Note that this is OK because the data structure we
* are constructing is only used by the planner --- the executor
* still needs to insert into "invalid" indexes, if they're marked
* IndexIsReady.
*/
if (!IndexIsValid(index))
{
index_close(indexRelation, NoLock);
continue;
}
/*
* If the index is valid, but cannot yet be used, ignore it; but
* mark the plan we are generating as transient. See
* src/backend/access/heap/README.HOT for discussion.
*/
if (index->indcheckxmin &&
!TransactionIdPrecedes(HeapTupleHeaderGetXmin(indexRelation->rd_indextuple->t_data),
TransactionXmin))
{
root->glob->transientPlan = true;
index_close(indexRelation, NoLock);
continue;
}
info = makeNode(IndexOptInfo);
info->indexoid = index->indexrelid;
info->reltablespace =
RelationGetForm(indexRelation)->reltablespace;
info->rel = rel;
info->ncolumns = ncolumns = index->indnatts;
info->indexkeys = (int *) palloc(sizeof(int) * ncolumns);
info->indexcollations = (Oid *) palloc(sizeof(Oid) * ncolumns);
info->opfamily = (Oid *) palloc(sizeof(Oid) * ncolumns);
info->opcintype = (Oid *) palloc(sizeof(Oid) * ncolumns);
for (i = 0; i < ncolumns; i++)
{
info->indexkeys[i] = index->indkey.values[i];
info->indexcollations[i] = indexRelation->rd_indcollation[i];
info->opfamily[i] = indexRelation->rd_opfamily[i];
info->opcintype[i] = indexRelation->rd_opcintype[i];
}
info->relam = indexRelation->rd_rel->relam;
info->amcostestimate = indexRelation->rd_am->amcostestimate;
info->canreturn = index_can_return(indexRelation);
info->amcanorderbyop = indexRelation->rd_am->amcanorderbyop;
info->amoptionalkey = indexRelation->rd_am->amoptionalkey;
info->amsearcharray = indexRelation->rd_am->amsearcharray;
info->amsearchnulls = indexRelation->rd_am->amsearchnulls;
info->amhasgettuple = OidIsValid(indexRelation->rd_am->amgettuple);
info->amhasgetbitmap = OidIsValid(indexRelation->rd_am->amgetbitmap);
/*
* Fetch the ordering information for the index, if any.
*/
if (info->relam == BTREE_AM_OID)
{
/*
* If it's a btree index, we can use its opfamily OIDs
* directly as the sort ordering opfamily OIDs.
*/
Assert(indexRelation->rd_am->amcanorder);
info->sortopfamily = info->opfamily;
info->reverse_sort = (bool *) palloc(sizeof(bool) * ncolumns);
info->nulls_first = (bool *) palloc(sizeof(bool) * ncolumns);
for (i = 0; i < ncolumns; i++)
{
int16 opt = indexRelation->rd_indoption[i];
info->reverse_sort[i] = (opt & INDOPTION_DESC) != 0;
info->nulls_first[i] = (opt & INDOPTION_NULLS_FIRST) != 0;
}
}
else if (indexRelation->rd_am->amcanorder)
{
/*
* Otherwise, identify the corresponding btree opfamilies by
* trying to map this index's "<" operators into btree. Since
* "<" uniquely defines the behavior of a sort order, this is
* a sufficient test.
*
* XXX This method is rather slow and also requires the
* undesirable assumption that the other index AM numbers its
* strategies the same as btree. It'd be better to have a way
* to explicitly declare the corresponding btree opfamily for
* each opfamily of the other index type. But given the lack
* of current or foreseeable amcanorder index types, it's not
* worth expending more effort on now.
*/
info->sortopfamily = (Oid *) palloc(sizeof(Oid) * ncolumns);
info->reverse_sort = (bool *) palloc(sizeof(bool) * ncolumns);
info->nulls_first = (bool *) palloc(sizeof(bool) * ncolumns);
for (i = 0; i < ncolumns; i++)
{
int16 opt = indexRelation->rd_indoption[i];
Oid ltopr;
Oid btopfamily;
Oid btopcintype;
int16 btstrategy;
info->reverse_sort[i] = (opt & INDOPTION_DESC) != 0;
info->nulls_first[i] = (opt & INDOPTION_NULLS_FIRST) != 0;
ltopr = get_opfamily_member(info->opfamily[i],
info->opcintype[i],
info->opcintype[i],
BTLessStrategyNumber);
if (OidIsValid(ltopr) &&
get_ordering_op_properties(ltopr,
&btopfamily,
&btopcintype,
&btstrategy) &&
btopcintype == info->opcintype[i] &&
btstrategy == BTLessStrategyNumber)
{
/* Successful mapping */
info->sortopfamily[i] = btopfamily;
}
else
{
/* Fail ... quietly treat index as unordered */
info->sortopfamily = NULL;
info->reverse_sort = NULL;
info->nulls_first = NULL;
break;
}
}
}
else
{
info->sortopfamily = NULL;
info->reverse_sort = NULL;
info->nulls_first = NULL;
}
/*
* Fetch the index expressions and predicate, if any. We must
* modify the copies we obtain from the relcache to have the
* correct varno for the parent relation, so that they match up
* correctly against qual clauses.
*/
info->indexprs = RelationGetIndexExpressions(indexRelation);
info->indpred = RelationGetIndexPredicate(indexRelation);
if (info->indexprs && varno != 1)
ChangeVarNodes((Node *) info->indexprs, 1, varno, 0);
if (info->indpred && varno != 1)
ChangeVarNodes((Node *) info->indpred, 1, varno, 0);
/* Build targetlist using the completed indexprs data */
info->indextlist = build_index_tlist(root, info, relation);
info->predOK = false; /* set later in indxpath.c */
info->unique = index->indisunique;
info->immediate = index->indimmediate;
info->hypothetical = false;
/*
* Estimate the index size. If it's not a partial index, we lock
* the number-of-tuples estimate to equal the parent table; if it
* is partial then we have to use the same methods as we would for
* a table, except we can be sure that the index is not larger
* than the table.
*/
if (info->indpred == NIL)
{
info->pages = RelationGetNumberOfBlocks(indexRelation);
info->tuples = rel->tuples;
}
else
{
double allvisfrac; /* dummy */
estimate_rel_size(indexRelation, NULL,
&info->pages, &info->tuples, &allvisfrac);
if (info->tuples > rel->tuples)
info->tuples = rel->tuples;
}
if (info->relam == BTREE_AM_OID)
{
/* For btrees, get tree height while we have the index open */
info->tree_height = _bt_getrootheight(indexRelation);
}
else
{
/* For other index types, just set it to "unknown" for now */
info->tree_height = -1;
}
index_close(indexRelation, NoLock);
indexinfos = lcons(info, indexinfos);
}
list_free(indexoidlist);
}
rel->indexlist = indexinfos;
/* Grab the fdwroutine info using the relcache, while we have it */
if (relation->rd_rel->relkind == RELKIND_FOREIGN_TABLE)
rel->fdwroutine = GetFdwRoutineForRelation(relation, true);
else
rel->fdwroutine = NULL;
heap_close(relation, NoLock);
/*
* Allow a plugin to editorialize on the info we obtained from the
* catalogs. Actions might include altering the assumed relation size,
* removing an index, or adding a hypothetical index to the indexlist.
*/
if (get_relation_info_hook)
(*get_relation_info_hook) (root, relationObjectId, inhparent, rel);
}
| bool has_unique_index | ( | RelOptInfo * | rel, | |
| AttrNumber | attno | |||
| ) |
Definition at line 1109 of file plancat.c.
References IndexOptInfo::indexkeys, RelOptInfo::indexlist, IndexOptInfo::indpred, lfirst, IndexOptInfo::ncolumns, NIL, IndexOptInfo::predOK, and IndexOptInfo::unique.
Referenced by examine_variable().
{
ListCell *ilist;
foreach(ilist, rel->indexlist)
{
IndexOptInfo *index = (IndexOptInfo *) lfirst(ilist);
/*
* Note: ignore partial indexes, since they don't allow us to conclude
* that all attr values are distinct, *unless* they are marked predOK
* which means we know the index's predicate is satisfied by the
* query. We don't take any interest in expressional indexes either.
* Also, a multicolumn unique index doesn't allow us to conclude that
* just the specified attr is unique.
*/
if (index->unique &&
index->ncolumns == 1 &&
index->indexkeys[0] == attno &&
(index->indpred == NIL || index->predOK))
return true;
}
return false;
}
| Selectivity join_selectivity | ( | PlannerInfo * | root, | |
| Oid | operatorid, | |||
| List * | args, | |||
| Oid | inputcollid, | |||
| JoinType | jointype, | |||
| SpecialJoinInfo * | sjinfo | |||
| ) |
Definition at line 1065 of file plancat.c.
References DatumGetFloat8, elog, ERROR, get_oprjoin(), Int16GetDatum, ObjectIdGetDatum, OidFunctionCall5Coll(), and PointerGetDatum.
Referenced by clause_selectivity(), and rowcomparesel().
{
RegProcedure oprjoin = get_oprjoin(operatorid);
float8 result;
/*
* if the oprjoin procedure is missing for whatever reason, use a
* selectivity of 0.5
*/
if (!oprjoin)
return (Selectivity) 0.5;
result = DatumGetFloat8(OidFunctionCall5Coll(oprjoin,
inputcollid,
PointerGetDatum(root),
ObjectIdGetDatum(operatorid),
PointerGetDatum(args),
Int16GetDatum(jointype),
PointerGetDatum(sjinfo)));
if (result < 0.0 || result > 1.0)
elog(ERROR, "invalid join selectivity: %f", result);
return (Selectivity) result;
}
| bool relation_excluded_by_constraints | ( | PlannerInfo * | root, | |
| RelOptInfo * | rel, | |||
| RangeTblEntry * | rte | |||
| ) |
Definition at line 747 of file plancat.c.
References RelOptInfo::baserestrictinfo, RestrictInfo::clause, constraint_exclusion, CONSTRAINT_EXCLUSION_OFF, CONSTRAINT_EXCLUSION_PARTITION, contain_mutable_functions(), get_relation_constraints(), PlannerInfo::hasInheritedTarget, RangeTblEntry::inh, lappend(), lfirst, PlannerInfo::parse, predicate_refuted_by(), RangeTblEntry::relid, RelOptInfo::relid, RELOPT_BASEREL, RELOPT_OTHER_MEMBER_REL, RelOptInfo::reloptkind, Query::resultRelation, RTE_RELATION, and RangeTblEntry::rtekind.
Referenced by set_append_rel_size(), and set_rel_size().
{
List *safe_restrictions;
List *constraint_pred;
List *safe_constraints;
ListCell *lc;
/* Skip the test if constraint exclusion is disabled for the rel */
if (constraint_exclusion == CONSTRAINT_EXCLUSION_OFF ||
(constraint_exclusion == CONSTRAINT_EXCLUSION_PARTITION &&
!(rel->reloptkind == RELOPT_OTHER_MEMBER_REL ||
(root->hasInheritedTarget &&
rel->reloptkind == RELOPT_BASEREL &&
rel->relid == root->parse->resultRelation))))
return false;
/*
* Check for self-contradictory restriction clauses. We dare not make
* deductions with non-immutable functions, but any immutable clauses that
* are self-contradictory allow us to conclude the scan is unnecessary.
*
* Note: strip off RestrictInfo because predicate_refuted_by() isn't
* expecting to see any in its predicate argument.
*/
safe_restrictions = NIL;
foreach(lc, rel->baserestrictinfo)
{
RestrictInfo *rinfo = (RestrictInfo *) lfirst(lc);
if (!contain_mutable_functions((Node *) rinfo->clause))
safe_restrictions = lappend(safe_restrictions, rinfo->clause);
}
if (predicate_refuted_by(safe_restrictions, safe_restrictions))
return true;
/* Only plain relations have constraints */
if (rte->rtekind != RTE_RELATION || rte->inh)
return false;
/*
* OK to fetch the constraint expressions. Include "col IS NOT NULL"
* expressions for attnotnull columns, in case we can refute those.
*/
constraint_pred = get_relation_constraints(root, rte->relid, rel, true);
/*
* We do not currently enforce that CHECK constraints contain only
* immutable functions, so it's necessary to check here. We daren't draw
* conclusions from plan-time evaluation of non-immutable functions. Since
* they're ANDed, we can just ignore any mutable constraints in the list,
* and reason about the rest.
*/
safe_constraints = NIL;
foreach(lc, constraint_pred)
{
Node *pred = (Node *) lfirst(lc);
if (!contain_mutable_functions(pred))
safe_constraints = lappend(safe_constraints, pred);
}
/*
* The constraints are effectively ANDed together, so we can just try to
* refute the entire collection at once. This may allow us to make proofs
* that would fail if we took them individually.
*
* Note: we use rel->baserestrictinfo, not safe_restrictions as might seem
* an obvious optimization. Some of the clauses might be OR clauses that
* have volatile and nonvolatile subclauses, and it's OK to make
* deductions with the nonvolatile parts.
*/
if (predicate_refuted_by(safe_constraints, rel->baserestrictinfo))
return true;
return false;
}
| Selectivity restriction_selectivity | ( | PlannerInfo * | root, | |
| Oid | operatorid, | |||
| List * | args, | |||
| Oid | inputcollid, | |||
| int | varRelid | |||
| ) |
Definition at line 1028 of file plancat.c.
References DatumGetFloat8, elog, ERROR, get_oprrest(), Int32GetDatum, ObjectIdGetDatum, OidFunctionCall4Coll(), and PointerGetDatum.
Referenced by clause_selectivity(), and rowcomparesel().
{
RegProcedure oprrest = get_oprrest(operatorid);
float8 result;
/*
* if the oprrest procedure is missing for whatever reason, use a
* selectivity of 0.5
*/
if (!oprrest)
return (Selectivity) 0.5;
result = DatumGetFloat8(OidFunctionCall4Coll(oprrest,
inputcollid,
PointerGetDatum(root),
ObjectIdGetDatum(operatorid),
PointerGetDatum(args),
Int32GetDatum(varRelid)));
if (result < 0.0 || result > 1.0)
elog(ERROR, "invalid restriction selectivity: %f", result);
return (Selectivity) result;
}
| PGDLLIMPORT get_relation_info_hook_type get_relation_info_hook |
Definition at line 50 of file plancat.c.
Referenced by get_relation_info().
1.7.1