Header And Logo
|
#include "postgres.h"#include "catalog/pg_type.h"#include "nodes/nodeFuncs.h"#include "optimizer/clauses.h"#include "optimizer/joininfo.h"#include "optimizer/pathnode.h"#include "optimizer/paths.h"#include "optimizer/placeholder.h"#include "optimizer/planmain.h"#include "optimizer/planner.h"#include "optimizer/prep.h"#include "optimizer/restrictinfo.h"#include "optimizer/var.h"#include "rewrite/rewriteManip.h"#include "utils/lsyscache.h"
Go to the source code of this file.
Functions | |
| static void | extract_lateral_references (PlannerInfo *root, RelOptInfo *brel, Index rtindex) |
| static void | add_lateral_info (PlannerInfo *root, Index rhs, Relids lhs) |
| static List * | deconstruct_recurse (PlannerInfo *root, Node *jtnode, bool below_outer_join, Relids *qualscope, Relids *inner_join_rels) |
| static SpecialJoinInfo * | make_outerjoininfo (PlannerInfo *root, Relids left_rels, Relids right_rels, Relids inner_join_rels, JoinType jointype, List *clause) |
| static void | distribute_qual_to_rels (PlannerInfo *root, Node *clause, bool is_deduced, bool below_outer_join, JoinType jointype, Relids qualscope, Relids ojscope, Relids outerjoin_nonnullable, Relids deduced_nullable_relids) |
| static bool | check_outerjoin_delay (PlannerInfo *root, Relids *relids_p, Relids *nullable_relids_p, bool is_pushed_down) |
| static bool | check_equivalence_delay (PlannerInfo *root, RestrictInfo *restrictinfo) |
| static bool | check_redundant_nullability_qual (PlannerInfo *root, Node *clause) |
| static void | check_mergejoinable (RestrictInfo *restrictinfo) |
| static void | check_hashjoinable (RestrictInfo *restrictinfo) |
| void | add_base_rels_to_query (PlannerInfo *root, Node *jtnode) |
| void | build_base_rel_tlists (PlannerInfo *root, List *final_tlist) |
| void | add_vars_to_targetlist (PlannerInfo *root, List *vars, Relids where_needed, bool create_new_ph) |
| void | find_lateral_references (PlannerInfo *root) |
| void | create_lateral_join_info (PlannerInfo *root) |
| List * | deconstruct_jointree (PlannerInfo *root) |
| void | distribute_restrictinfo_to_rels (PlannerInfo *root, RestrictInfo *restrictinfo) |
| void | process_implied_equality (PlannerInfo *root, Oid opno, Oid collation, Expr *item1, Expr *item2, Relids qualscope, Relids nullable_relids, bool below_outer_join, bool both_const) |
| RestrictInfo * | build_implied_join_equality (Oid opno, Oid collation, Expr *item1, Expr *item2, Relids qualscope, Relids nullable_relids) |
Variables | |
| int | from_collapse_limit |
| int | join_collapse_limit |
| void add_base_rels_to_query | ( | PlannerInfo * | root, | |
| Node * | jtnode | |||
| ) |
Definition at line 88 of file initsplan.c.
References add_base_rels_to_query(), build_simple_rel(), elog, ERROR, FromExpr::fromlist, IsA, JoinExpr::larg, lfirst, nodeTag, NULL, JoinExpr::rarg, and RELOPT_BASEREL.
Referenced by add_base_rels_to_query(), and query_planner().
{
if (jtnode == NULL)
return;
if (IsA(jtnode, RangeTblRef))
{
int varno = ((RangeTblRef *) jtnode)->rtindex;
(void) build_simple_rel(root, varno, RELOPT_BASEREL);
}
else if (IsA(jtnode, FromExpr))
{
FromExpr *f = (FromExpr *) jtnode;
ListCell *l;
foreach(l, f->fromlist)
add_base_rels_to_query(root, lfirst(l));
}
else if (IsA(jtnode, JoinExpr))
{
JoinExpr *j = (JoinExpr *) jtnode;
add_base_rels_to_query(root, j->larg);
add_base_rels_to_query(root, j->rarg);
}
else
elog(ERROR, "unrecognized node type: %d",
(int) nodeTag(jtnode));
}
| static void add_lateral_info | ( | PlannerInfo * | root, | |
| Index | rhs, | |||
| Relids | lhs | |||
| ) | [static] |
Definition at line 473 of file initsplan.c.
References Assert, bms_free(), bms_is_member(), bms_is_subset(), lappend(), PlannerInfo::lateral_info_list, LateralJoinInfo::lateral_lhs, LateralJoinInfo::lateral_rhs, lfirst, and makeNode.
Referenced by create_lateral_join_info().
{
LateralJoinInfo *ljinfo;
ListCell *l;
Assert(!bms_is_member(rhs, lhs));
/*
* If an existing list member has the same RHS and an LHS that is a subset
* of the new one, it's redundant, but we don't trouble to get rid of it.
* The only case that is really worth worrying about is identical entries,
* and we handle that well enough with this simple logic.
*/
foreach(l, root->lateral_info_list)
{
ljinfo = (LateralJoinInfo *) lfirst(l);
if (rhs == ljinfo->lateral_rhs &&
bms_is_subset(lhs, ljinfo->lateral_lhs))
{
bms_free(lhs);
return;
}
}
/* Not there, so make a new entry */
ljinfo = makeNode(LateralJoinInfo);
ljinfo->lateral_rhs = rhs;
ljinfo->lateral_lhs = lhs;
root->lateral_info_list = lappend(root->lateral_info_list, ljinfo);
}
| void add_vars_to_targetlist | ( | PlannerInfo * | root, | |
| List * | vars, | |||
| Relids | where_needed, | |||
| bool | create_new_ph | |||
| ) |
Definition at line 163 of file initsplan.c.
References Assert, RelOptInfo::attr_needed, bms_add_members(), bms_is_empty(), bms_is_subset(), copyObject(), elog, ERROR, find_base_rel(), find_placeholder_info(), IsA, lappend(), lfirst, mark_placeholder_maybe_needed(), RelOptInfo::min_attr, nodeTag, NULL, PlaceHolderInfo::ph_may_need, PlaceHolderInfo::ph_needed, RelOptInfo::reltargetlist, RangeQueryClause::var, Var::varattno, and Var::varno.
Referenced by build_base_rel_tlists(), distribute_qual_to_rels(), extract_lateral_references(), fix_placeholder_input_needed_levels(), and generate_base_implied_equalities_no_const().
{
ListCell *temp;
Assert(!bms_is_empty(where_needed));
foreach(temp, vars)
{
Node *node = (Node *) lfirst(temp);
if (IsA(node, Var))
{
Var *var = (Var *) node;
RelOptInfo *rel = find_base_rel(root, var->varno);
int attno = var->varattno;
Assert(attno >= rel->min_attr && attno <= rel->max_attr);
attno -= rel->min_attr;
if (rel->attr_needed[attno] == NULL)
{
/* Variable not yet requested, so add to reltargetlist */
/* XXX is copyObject necessary here? */
rel->reltargetlist = lappend(rel->reltargetlist,
copyObject(var));
}
rel->attr_needed[attno] = bms_add_members(rel->attr_needed[attno],
where_needed);
}
else if (IsA(node, PlaceHolderVar))
{
PlaceHolderVar *phv = (PlaceHolderVar *) node;
PlaceHolderInfo *phinfo = find_placeholder_info(root, phv,
create_new_ph);
/* Always adjust ph_needed */
phinfo->ph_needed = bms_add_members(phinfo->ph_needed,
where_needed);
/*
* If we are creating PlaceHolderInfos, mark them with the correct
* maybe-needed locations. Otherwise, it's too late to change
* that, so we'd better not have set ph_needed to more than
* ph_may_need.
*/
if (create_new_ph)
mark_placeholder_maybe_needed(root, phinfo, where_needed);
else
Assert(bms_is_subset(phinfo->ph_needed, phinfo->ph_may_need));
}
else
elog(ERROR, "unrecognized node type: %d", (int) nodeTag(node));
}
}
| void build_base_rel_tlists | ( | PlannerInfo * | root, | |
| List * | final_tlist | |||
| ) |
Definition at line 134 of file initsplan.c.
References add_vars_to_targetlist(), bms_make_singleton(), list_free(), NIL, pull_var_clause(), PVC_INCLUDE_PLACEHOLDERS, and PVC_RECURSE_AGGREGATES.
Referenced by query_planner().
{
List *tlist_vars = pull_var_clause((Node *) final_tlist,
PVC_RECURSE_AGGREGATES,
PVC_INCLUDE_PLACEHOLDERS);
if (tlist_vars != NIL)
{
add_vars_to_targetlist(root, tlist_vars, bms_make_singleton(0), true);
list_free(tlist_vars);
}
}
| RestrictInfo* build_implied_join_equality | ( | Oid | opno, | |
| Oid | collation, | |||
| Expr * | item1, | |||
| Expr * | item2, | |||
| Relids | qualscope, | |||
| Relids | nullable_relids | |||
| ) |
Definition at line 1803 of file initsplan.c.
References BOOLOID, check_hashjoinable(), check_mergejoinable(), copyObject(), InvalidOid, make_opclause(), make_restrictinfo(), and NULL.
Referenced by create_join_clause(), reconsider_full_join_clause(), and reconsider_outer_join_clause().
{
RestrictInfo *restrictinfo;
Expr *clause;
/*
* Build the new clause. Copy to ensure it shares no substructure with
* original (this is necessary in case there are subselects in there...)
*/
clause = make_opclause(opno,
BOOLOID, /* opresulttype */
false, /* opretset */
(Expr *) copyObject(item1),
(Expr *) copyObject(item2),
InvalidOid,
collation);
/*
* Build the RestrictInfo node itself.
*/
restrictinfo = make_restrictinfo(clause,
true, /* is_pushed_down */
false, /* outerjoin_delayed */
false, /* pseudoconstant */
qualscope, /* required_relids */
NULL, /* outer_relids */
nullable_relids); /* nullable_relids */
/* Set mergejoinability/hashjoinability flags */
check_mergejoinable(restrictinfo);
check_hashjoinable(restrictinfo);
return restrictinfo;
}
| static bool check_equivalence_delay | ( | PlannerInfo * | root, | |
| RestrictInfo * | restrictinfo | |||
| ) | [static] |
Definition at line 1589 of file initsplan.c.
References bms_copy(), check_outerjoin_delay(), PlannerInfo::join_info_list, RestrictInfo::left_relids, NIL, and RestrictInfo::right_relids.
Referenced by distribute_qual_to_rels().
{
Relids relids;
Relids nullable_relids;
/* fast path if no special joins */
if (root->join_info_list == NIL)
return true;
/* must copy restrictinfo's relids to avoid changing it */
relids = bms_copy(restrictinfo->left_relids);
/* check left side does not need delay */
if (check_outerjoin_delay(root, &relids, &nullable_relids, true))
return false;
/* and similarly for the right side */
relids = bms_copy(restrictinfo->right_relids);
if (check_outerjoin_delay(root, &relids, &nullable_relids, true))
return false;
return true;
}
| static void check_hashjoinable | ( | RestrictInfo * | restrictinfo | ) | [static] |
Definition at line 1897 of file initsplan.c.
References RestrictInfo::clause, contain_volatile_functions(), exprType(), RestrictInfo::hashjoinoperator, is_opclause, linitial, list_length(), op_hashjoinable(), and RestrictInfo::pseudoconstant.
Referenced by build_implied_join_equality(), and distribute_restrictinfo_to_rels().
{
Expr *clause = restrictinfo->clause;
Oid opno;
Node *leftarg;
if (restrictinfo->pseudoconstant)
return;
if (!is_opclause(clause))
return;
if (list_length(((OpExpr *) clause)->args) != 2)
return;
opno = ((OpExpr *) clause)->opno;
leftarg = linitial(((OpExpr *) clause)->args);
if (op_hashjoinable(opno, exprType(leftarg)) &&
!contain_volatile_functions((Node *) clause))
restrictinfo->hashjoinoperator = opno;
}
| static void check_mergejoinable | ( | RestrictInfo * | restrictinfo | ) | [static] |
Definition at line 1860 of file initsplan.c.
References RestrictInfo::clause, contain_volatile_functions(), exprType(), get_mergejoin_opfamilies(), is_opclause, linitial, list_length(), RestrictInfo::mergeopfamilies, op_mergejoinable(), and RestrictInfo::pseudoconstant.
Referenced by build_implied_join_equality(), and distribute_qual_to_rels().
{
Expr *clause = restrictinfo->clause;
Oid opno;
Node *leftarg;
if (restrictinfo->pseudoconstant)
return;
if (!is_opclause(clause))
return;
if (list_length(((OpExpr *) clause)->args) != 2)
return;
opno = ((OpExpr *) clause)->opno;
leftarg = linitial(((OpExpr *) clause)->args);
if (op_mergejoinable(opno, exprType(leftarg)) &&
!contain_volatile_functions((Node *) clause))
restrictinfo->mergeopfamilies = get_mergejoin_opfamilies(opno);
/*
* Note: op_mergejoinable is just a hint; if we fail to find the operator
* in any btree opfamilies, mergeopfamilies remains NIL and so the clause
* is not treated as mergejoinable.
*/
}
| static bool check_outerjoin_delay | ( | PlannerInfo * | root, | |
| Relids * | relids_p, | |||
| Relids * | nullable_relids_p, | |||
| bool | is_pushed_down | |||
| ) | [static] |
Definition at line 1505 of file initsplan.c.
References bms_add_members(), bms_copy(), bms_free(), bms_int_members(), bms_is_subset(), bms_overlap(), SpecialJoinInfo::delay_upper_joins, JOIN_FULL, PlannerInfo::join_info_list, SpecialJoinInfo::jointype, lfirst, SpecialJoinInfo::min_lefthand, SpecialJoinInfo::min_righthand, and NIL.
Referenced by check_equivalence_delay(), and distribute_qual_to_rels().
{
Relids relids;
Relids nullable_relids;
bool outerjoin_delayed;
bool found_some;
/* fast path if no special joins */
if (root->join_info_list == NIL)
{
*nullable_relids_p = NULL;
return false;
}
/* must copy relids because we need the original value at the end */
relids = bms_copy(*relids_p);
nullable_relids = NULL;
outerjoin_delayed = false;
do
{
ListCell *l;
found_some = false;
foreach(l, root->join_info_list)
{
SpecialJoinInfo *sjinfo = (SpecialJoinInfo *) lfirst(l);
/* do we reference any nullable rels of this OJ? */
if (bms_overlap(relids, sjinfo->min_righthand) ||
(sjinfo->jointype == JOIN_FULL &&
bms_overlap(relids, sjinfo->min_lefthand)))
{
/* yes; have we included all its rels in relids? */
if (!bms_is_subset(sjinfo->min_lefthand, relids) ||
!bms_is_subset(sjinfo->min_righthand, relids))
{
/* no, so add them in */
relids = bms_add_members(relids, sjinfo->min_lefthand);
relids = bms_add_members(relids, sjinfo->min_righthand);
outerjoin_delayed = true;
/* we'll need another iteration */
found_some = true;
}
/* track all the nullable rels of relevant OJs */
nullable_relids = bms_add_members(nullable_relids,
sjinfo->min_righthand);
if (sjinfo->jointype == JOIN_FULL)
nullable_relids = bms_add_members(nullable_relids,
sjinfo->min_lefthand);
/* set delay_upper_joins if needed */
if (is_pushed_down && sjinfo->jointype != JOIN_FULL &&
bms_overlap(relids, sjinfo->min_lefthand))
sjinfo->delay_upper_joins = true;
}
}
} while (found_some);
/* identify just the actually-referenced nullable rels */
nullable_relids = bms_int_members(nullable_relids, *relids_p);
/* replace *relids_p, and return nullable_relids */
bms_free(*relids_p);
*relids_p = relids;
*nullable_relids_p = nullable_relids;
return outerjoin_delayed;
}
| static bool check_redundant_nullability_qual | ( | PlannerInfo * | root, | |
| Node * | clause | |||
| ) | [static] |
Definition at line 1624 of file initsplan.c.
References bms_is_member(), find_forced_null_var(), JOIN_ANTI, PlannerInfo::join_info_list, SpecialJoinInfo::jointype, lfirst, NULL, SpecialJoinInfo::syn_righthand, and Var::varno.
Referenced by distribute_qual_to_rels().
{
Var *forced_null_var;
Index forced_null_rel;
ListCell *lc;
/* Check for IS NULL, and identify the Var forced to NULL */
forced_null_var = find_forced_null_var(clause);
if (forced_null_var == NULL)
return false;
forced_null_rel = forced_null_var->varno;
/*
* If the Var comes from the nullable side of a lower antijoin, the IS
* NULL condition is necessarily true.
*/
foreach(lc, root->join_info_list)
{
SpecialJoinInfo *sjinfo = (SpecialJoinInfo *) lfirst(lc);
if (sjinfo->jointype == JOIN_ANTI &&
bms_is_member(forced_null_rel, sjinfo->syn_righthand))
return true;
}
return false;
}
| void create_lateral_join_info | ( | PlannerInfo * | root | ) |
Definition at line 377 of file initsplan.c.
References add_lateral_info(), PlannerInfo::append_rel_list, Assert, bms_add_member(), bms_add_members(), bms_copy(), bms_is_empty(), bms_make_singleton(), AppendRelInfo::child_relid, find_placeholder_info(), PlannerInfo::hasLateralRTEs, RangeTblEntry::inh, IsA, RelOptInfo::lateral_relids, RelOptInfo::lateral_vars, lfirst, NULL, AppendRelInfo::parent_relid, PlaceHolderInfo::ph_eval_at, RelOptInfo::relid, RELOPT_BASEREL, RELOPT_OTHER_MEMBER_REL, RelOptInfo::reloptkind, PlannerInfo::simple_rel_array, PlannerInfo::simple_rel_array_size, PlannerInfo::simple_rte_array, RangeQueryClause::var, and Var::varno.
Referenced by query_planner().
{
Index rti;
/* We need do nothing if the query contains no LATERAL RTEs */
if (!root->hasLateralRTEs)
return;
/*
* Examine all baserels (the rel array has been set up by now).
*/
for (rti = 1; rti < root->simple_rel_array_size; rti++)
{
RelOptInfo *brel = root->simple_rel_array[rti];
Relids lateral_relids;
ListCell *lc;
/* there may be empty slots corresponding to non-baserel RTEs */
if (brel == NULL)
continue;
Assert(brel->relid == rti); /* sanity check on array */
/* ignore RTEs that are "other rels" */
if (brel->reloptkind != RELOPT_BASEREL)
continue;
lateral_relids = NULL;
/* consider each laterally-referenced Var or PHV */
foreach(lc, brel->lateral_vars)
{
Node *node = (Node *) lfirst(lc);
if (IsA(node, Var))
{
Var *var = (Var *) node;
add_lateral_info(root, rti, bms_make_singleton(var->varno));
lateral_relids = bms_add_member(lateral_relids,
var->varno);
}
else if (IsA(node, PlaceHolderVar))
{
PlaceHolderVar *phv = (PlaceHolderVar *) node;
PlaceHolderInfo *phinfo = find_placeholder_info(root, phv,
false);
add_lateral_info(root, rti, bms_copy(phinfo->ph_eval_at));
lateral_relids = bms_add_members(lateral_relids,
phinfo->ph_eval_at);
}
else
Assert(false);
}
/* We now know all the relids needed for lateral refs in this rel */
if (bms_is_empty(lateral_relids))
continue; /* ensure lateral_relids is NULL if empty */
brel->lateral_relids = lateral_relids;
/*
* If it's an appendrel parent, copy its lateral_relids to each child
* rel. We intentionally give each child rel the same minimum
* parameterization, even though it's quite possible that some don't
* reference all the lateral rels. This is because any append path
* for the parent will have to have the same parameterization for
* every child anyway, and there's no value in forcing extra
* reparameterize_path() calls.
*/
if (root->simple_rte_array[rti]->inh)
{
foreach(lc, root->append_rel_list)
{
AppendRelInfo *appinfo = (AppendRelInfo *) lfirst(lc);
RelOptInfo *childrel;
if (appinfo->parent_relid != rti)
continue;
childrel = root->simple_rel_array[appinfo->child_relid];
Assert(childrel->reloptkind == RELOPT_OTHER_MEMBER_REL);
Assert(childrel->lateral_relids == NULL);
childrel->lateral_relids = lateral_relids;
}
}
}
}
| List* deconstruct_jointree | ( | PlannerInfo * | root | ) |
Definition at line 538 of file initsplan.c.
References Assert, deconstruct_recurse(), IsA, Query::jointree, NULL, and PlannerInfo::parse.
Referenced by query_planner().
| static List * deconstruct_recurse | ( | PlannerInfo * | root, | |
| Node * | jtnode, | |||
| bool | below_outer_join, | |||
| Relids * | qualscope, | |||
| Relids * | inner_join_rels | |||
| ) | [static] |
Definition at line 571 of file initsplan.c.
References bms_add_members(), bms_make_singleton(), bms_union(), distribute_qual_to_rels(), elog, ERROR, from_collapse_limit, FromExpr::fromlist, IsA, JOIN_ANTI, join_collapse_limit, JOIN_FULL, PlannerInfo::join_info_list, JOIN_INNER, JOIN_LEFT, JOIN_SEMI, JoinExpr::jointype, lappend(), JoinExpr::larg, lfirst, linitial, list_concat(), list_length(), list_make1, list_make2, make_outerjoininfo(), SpecialJoinInfo::min_lefthand, SpecialJoinInfo::min_righthand, nodeTag, NULL, JoinExpr::quals, FromExpr::quals, JoinExpr::rarg, remaining, and update_placeholder_eval_levels().
Referenced by deconstruct_jointree().
{
List *joinlist;
if (jtnode == NULL)
{
*qualscope = NULL;
*inner_join_rels = NULL;
return NIL;
}
if (IsA(jtnode, RangeTblRef))
{
int varno = ((RangeTblRef *) jtnode)->rtindex;
/* No quals to deal with, just return correct result */
*qualscope = bms_make_singleton(varno);
/* A single baserel does not create an inner join */
*inner_join_rels = NULL;
joinlist = list_make1(jtnode);
}
else if (IsA(jtnode, FromExpr))
{
FromExpr *f = (FromExpr *) jtnode;
int remaining;
ListCell *l;
/*
* First, recurse to handle child joins. We collapse subproblems into
* a single joinlist whenever the resulting joinlist wouldn't exceed
* from_collapse_limit members. Also, always collapse one-element
* subproblems, since that won't lengthen the joinlist anyway.
*/
*qualscope = NULL;
*inner_join_rels = NULL;
joinlist = NIL;
remaining = list_length(f->fromlist);
foreach(l, f->fromlist)
{
Relids sub_qualscope;
List *sub_joinlist;
int sub_members;
sub_joinlist = deconstruct_recurse(root, lfirst(l),
below_outer_join,
&sub_qualscope,
inner_join_rels);
*qualscope = bms_add_members(*qualscope, sub_qualscope);
sub_members = list_length(sub_joinlist);
remaining--;
if (sub_members <= 1 ||
list_length(joinlist) + sub_members + remaining <= from_collapse_limit)
joinlist = list_concat(joinlist, sub_joinlist);
else
joinlist = lappend(joinlist, sub_joinlist);
}
/*
* A FROM with more than one list element is an inner join subsuming
* all below it, so we should report inner_join_rels = qualscope. If
* there was exactly one element, we should (and already did) report
* whatever its inner_join_rels were. If there were no elements (is
* that possible?) the initialization before the loop fixed it.
*/
if (list_length(f->fromlist) > 1)
*inner_join_rels = *qualscope;
/*
* Now process the top-level quals.
*/
foreach(l, (List *) f->quals)
{
Node *qual = (Node *) lfirst(l);
distribute_qual_to_rels(root, qual,
false, below_outer_join, JOIN_INNER,
*qualscope, NULL, NULL, NULL);
}
}
else if (IsA(jtnode, JoinExpr))
{
JoinExpr *j = (JoinExpr *) jtnode;
Relids leftids,
rightids,
left_inners,
right_inners,
nonnullable_rels,
ojscope;
List *leftjoinlist,
*rightjoinlist;
SpecialJoinInfo *sjinfo;
ListCell *l;
/*
* Order of operations here is subtle and critical. First we recurse
* to handle sub-JOINs. Their join quals will be placed without
* regard for whether this level is an outer join, which is correct.
* Then we place our own join quals, which are restricted by lower
* outer joins in any case, and are forced to this level if this is an
* outer join and they mention the outer side. Finally, if this is an
* outer join, we create a join_info_list entry for the join. This
* will prevent quals above us in the join tree that use those rels
* from being pushed down below this level. (It's okay for upper
* quals to be pushed down to the outer side, however.)
*/
switch (j->jointype)
{
case JOIN_INNER:
leftjoinlist = deconstruct_recurse(root, j->larg,
below_outer_join,
&leftids, &left_inners);
rightjoinlist = deconstruct_recurse(root, j->rarg,
below_outer_join,
&rightids, &right_inners);
*qualscope = bms_union(leftids, rightids);
*inner_join_rels = *qualscope;
/* Inner join adds no restrictions for quals */
nonnullable_rels = NULL;
break;
case JOIN_LEFT:
case JOIN_ANTI:
leftjoinlist = deconstruct_recurse(root, j->larg,
below_outer_join,
&leftids, &left_inners);
rightjoinlist = deconstruct_recurse(root, j->rarg,
true,
&rightids, &right_inners);
*qualscope = bms_union(leftids, rightids);
*inner_join_rels = bms_union(left_inners, right_inners);
nonnullable_rels = leftids;
break;
case JOIN_SEMI:
leftjoinlist = deconstruct_recurse(root, j->larg,
below_outer_join,
&leftids, &left_inners);
rightjoinlist = deconstruct_recurse(root, j->rarg,
below_outer_join,
&rightids, &right_inners);
*qualscope = bms_union(leftids, rightids);
*inner_join_rels = bms_union(left_inners, right_inners);
/* Semi join adds no restrictions for quals */
nonnullable_rels = NULL;
break;
case JOIN_FULL:
leftjoinlist = deconstruct_recurse(root, j->larg,
true,
&leftids, &left_inners);
rightjoinlist = deconstruct_recurse(root, j->rarg,
true,
&rightids, &right_inners);
*qualscope = bms_union(leftids, rightids);
*inner_join_rels = bms_union(left_inners, right_inners);
/* each side is both outer and inner */
nonnullable_rels = *qualscope;
break;
default:
/* JOIN_RIGHT was eliminated during reduce_outer_joins() */
elog(ERROR, "unrecognized join type: %d",
(int) j->jointype);
nonnullable_rels = NULL; /* keep compiler quiet */
leftjoinlist = rightjoinlist = NIL;
break;
}
/*
* For an OJ, form the SpecialJoinInfo now, because we need the OJ's
* semantic scope (ojscope) to pass to distribute_qual_to_rels. But
* we mustn't add it to join_info_list just yet, because we don't want
* distribute_qual_to_rels to think it is an outer join below us.
*
* Semijoins are a bit of a hybrid: we build a SpecialJoinInfo, but we
* want ojscope = NULL for distribute_qual_to_rels.
*/
if (j->jointype != JOIN_INNER)
{
sjinfo = make_outerjoininfo(root,
leftids, rightids,
*inner_join_rels,
j->jointype,
(List *) j->quals);
if (j->jointype == JOIN_SEMI)
ojscope = NULL;
else
ojscope = bms_union(sjinfo->min_lefthand,
sjinfo->min_righthand);
}
else
{
sjinfo = NULL;
ojscope = NULL;
}
/* Process the qual clauses */
foreach(l, (List *) j->quals)
{
Node *qual = (Node *) lfirst(l);
distribute_qual_to_rels(root, qual,
false, below_outer_join, j->jointype,
*qualscope,
ojscope, nonnullable_rels, NULL);
}
/* Now we can add the SpecialJoinInfo to join_info_list */
if (sjinfo)
{
root->join_info_list = lappend(root->join_info_list, sjinfo);
/* Each time we do that, recheck placeholder eval levels */
update_placeholder_eval_levels(root, sjinfo);
}
/*
* Finally, compute the output joinlist. We fold subproblems together
* except at a FULL JOIN or where join_collapse_limit would be
* exceeded.
*/
if (j->jointype == JOIN_FULL)
{
/* force the join order exactly at this node */
joinlist = list_make1(list_make2(leftjoinlist, rightjoinlist));
}
else if (list_length(leftjoinlist) + list_length(rightjoinlist) <=
join_collapse_limit)
{
/* OK to combine subproblems */
joinlist = list_concat(leftjoinlist, rightjoinlist);
}
else
{
/* can't combine, but needn't force join order above here */
Node *leftpart,
*rightpart;
/* avoid creating useless 1-element sublists */
if (list_length(leftjoinlist) == 1)
leftpart = (Node *) linitial(leftjoinlist);
else
leftpart = (Node *) leftjoinlist;
if (list_length(rightjoinlist) == 1)
rightpart = (Node *) linitial(rightjoinlist);
else
rightpart = (Node *) rightjoinlist;
joinlist = list_make2(leftpart, rightpart);
}
}
else
{
elog(ERROR, "unrecognized node type: %d",
(int) nodeTag(jtnode));
joinlist = NIL; /* keep compiler quiet */
}
return joinlist;
}
| static void distribute_qual_to_rels | ( | PlannerInfo * | root, | |
| Node * | clause, | |||
| bool | is_deduced, | |||
| bool | below_outer_join, | |||
| JoinType | jointype, | |||
| Relids | qualscope, | |||
| Relids | ojscope, | |||
| Relids | outerjoin_nonnullable, | |||
| Relids | deduced_nullable_relids | |||
| ) | [static] |
Definition at line 1095 of file initsplan.c.
References add_vars_to_targetlist(), Assert, bms_copy(), bms_is_empty(), bms_is_subset(), bms_membership(), BMS_MULTIPLE, bms_overlap(), RestrictInfo::can_join, check_equivalence_delay(), check_mergejoinable(), check_outerjoin_delay(), check_redundant_nullability_qual(), contain_volatile_functions(), distribute_restrictinfo_to_rels(), elog, ERROR, PlannerInfo::full_join_clauses, get_relids_in_jointree(), PlannerInfo::hasLateralRTEs, PlannerInfo::hasPseudoConstantQuals, initialize_mergeclause_eclasses(), JOIN_FULL, Query::jointree, lappend(), PlannerInfo::left_join_clauses, RestrictInfo::left_relids, list_free(), make_restrictinfo(), RestrictInfo::mergeopfamilies, NULL, PlannerInfo::parse, process_equivalence(), pull_var_clause(), pull_varnos(), PVC_INCLUDE_PLACEHOLDERS, PVC_RECURSE_AGGREGATES, PlannerInfo::right_join_clauses, and RestrictInfo::right_relids.
Referenced by deconstruct_recurse(), and process_implied_equality().
{
Relids relids;
bool is_pushed_down;
bool outerjoin_delayed;
bool pseudoconstant = false;
bool maybe_equivalence;
bool maybe_outer_join;
Relids nullable_relids;
RestrictInfo *restrictinfo;
/*
* Retrieve all relids mentioned within the clause.
*/
relids = pull_varnos(clause);
/*
* Normally relids is a subset of qualscope, and we like to check that
* here as a crosscheck on the parser and rewriter. That need not be the
* case when there are LATERAL RTEs, however: the clause could contain
* references to rels outside its syntactic scope as a consequence of
* pull-up of such references from a LATERAL subquery below it. So, only
* check if the query contains no LATERAL RTEs.
*
* However, if it's an outer-join clause, we always insist that relids be
* a subset of ojscope. This is safe because is_simple_subquery()
* disallows pullup of LATERAL subqueries that could cause the restriction
* to be violated.
*/
if (!root->hasLateralRTEs && !bms_is_subset(relids, qualscope))
elog(ERROR, "JOIN qualification cannot refer to other relations");
if (ojscope && !bms_is_subset(relids, ojscope))
elog(ERROR, "JOIN qualification cannot refer to other relations");
/*
* If the clause is variable-free, our normal heuristic for pushing it
* down to just the mentioned rels doesn't work, because there are none.
*
* If the clause is an outer-join clause, we must force it to the OJ's
* semantic level to preserve semantics.
*
* Otherwise, when the clause contains volatile functions, we force it to
* be evaluated at its original syntactic level. This preserves the
* expected semantics.
*
* When the clause contains no volatile functions either, it is actually a
* pseudoconstant clause that will not change value during any one
* execution of the plan, and hence can be used as a one-time qual in a
* gating Result plan node. We put such a clause into the regular
* RestrictInfo lists for the moment, but eventually createplan.c will
* pull it out and make a gating Result node immediately above whatever
* plan node the pseudoconstant clause is assigned to. It's usually best
* to put a gating node as high in the plan tree as possible. If we are
* not below an outer join, we can actually push the pseudoconstant qual
* all the way to the top of the tree. If we are below an outer join, we
* leave the qual at its original syntactic level (we could push it up to
* just below the outer join, but that seems more complex than it's
* worth).
*/
if (bms_is_empty(relids))
{
if (ojscope)
{
/* clause is attached to outer join, eval it there */
relids = bms_copy(ojscope);
/* mustn't use as gating qual, so don't mark pseudoconstant */
}
else
{
/* eval at original syntactic level */
relids = bms_copy(qualscope);
if (!contain_volatile_functions(clause))
{
/* mark as gating qual */
pseudoconstant = true;
/* tell createplan.c to check for gating quals */
root->hasPseudoConstantQuals = true;
/* if not below outer join, push it to top of tree */
if (!below_outer_join)
{
relids =
get_relids_in_jointree((Node *) root->parse->jointree,
false);
qualscope = bms_copy(relids);
}
}
}
}
/*----------
* Check to see if clause application must be delayed by outer-join
* considerations.
*
* A word about is_pushed_down: we mark the qual as "pushed down" if
* it is (potentially) applicable at a level different from its original
* syntactic level. This flag is used to distinguish OUTER JOIN ON quals
* from other quals pushed down to the same joinrel. The rules are:
* WHERE quals and INNER JOIN quals: is_pushed_down = true.
* Non-degenerate OUTER JOIN quals: is_pushed_down = false.
* Degenerate OUTER JOIN quals: is_pushed_down = true.
* A "degenerate" OUTER JOIN qual is one that doesn't mention the
* non-nullable side, and hence can be pushed down into the nullable side
* without changing the join result. It is correct to treat it as a
* regular filter condition at the level where it is evaluated.
*
* Note: it is not immediately obvious that a simple boolean is enough
* for this: if for some reason we were to attach a degenerate qual to
* its original join level, it would need to be treated as an outer join
* qual there. However, this cannot happen, because all the rels the
* clause mentions must be in the outer join's min_righthand, therefore
* the join it needs must be formed before the outer join; and we always
* attach quals to the lowest level where they can be evaluated. But
* if we were ever to re-introduce a mechanism for delaying evaluation
* of "expensive" quals, this area would need work.
*----------
*/
if (is_deduced)
{
/*
* If the qual came from implied-equality deduction, it should not be
* outerjoin-delayed, else deducer blew it. But we can't check this
* because the join_info_list may now contain OJs above where the qual
* belongs. For the same reason, we must rely on caller to supply the
* correct nullable_relids set.
*/
Assert(!ojscope);
is_pushed_down = true;
outerjoin_delayed = false;
nullable_relids = deduced_nullable_relids;
/* Don't feed it back for more deductions */
maybe_equivalence = false;
maybe_outer_join = false;
}
else if (bms_overlap(relids, outerjoin_nonnullable))
{
/*
* The qual is attached to an outer join and mentions (some of the)
* rels on the nonnullable side, so it's not degenerate.
*
* We can't use such a clause to deduce equivalence (the left and
* right sides might be unequal above the join because one of them has
* gone to NULL) ... but we might be able to use it for more limited
* deductions, if it is mergejoinable. So consider adding it to the
* lists of set-aside outer-join clauses.
*/
is_pushed_down = false;
maybe_equivalence = false;
maybe_outer_join = true;
/* Check to see if must be delayed by lower outer join */
outerjoin_delayed = check_outerjoin_delay(root,
&relids,
&nullable_relids,
false);
/*
* Now force the qual to be evaluated exactly at the level of joining
* corresponding to the outer join. We cannot let it get pushed down
* into the nonnullable side, since then we'd produce no output rows,
* rather than the intended single null-extended row, for any
* nonnullable-side rows failing the qual.
*
* (Do this step after calling check_outerjoin_delay, because that
* trashes relids.)
*/
Assert(ojscope);
relids = ojscope;
Assert(!pseudoconstant);
}
else
{
/*
* Normal qual clause or degenerate outer-join clause. Either way, we
* can mark it as pushed-down.
*/
is_pushed_down = true;
/* Check to see if must be delayed by lower outer join */
outerjoin_delayed = check_outerjoin_delay(root,
&relids,
&nullable_relids,
true);
if (outerjoin_delayed)
{
/* Should still be a subset of current scope ... */
Assert(root->hasLateralRTEs || bms_is_subset(relids, qualscope));
Assert(ojscope == NULL || bms_is_subset(relids, ojscope));
/*
* Because application of the qual will be delayed by outer join,
* we mustn't assume its vars are equal everywhere.
*/
maybe_equivalence = false;
/*
* It's possible that this is an IS NULL clause that's redundant
* with a lower antijoin; if so we can just discard it. We need
* not test in any of the other cases, because this will only be
* possible for pushed-down, delayed clauses.
*/
if (check_redundant_nullability_qual(root, clause))
return;
}
else
{
/*
* Qual is not delayed by any lower outer-join restriction, so we
* can consider feeding it to the equivalence machinery. However,
* if it's itself within an outer-join clause, treat it as though
* it appeared below that outer join (note that we can only get
* here when the clause references only nullable-side rels).
*/
maybe_equivalence = true;
if (outerjoin_nonnullable != NULL)
below_outer_join = true;
}
/*
* Since it doesn't mention the LHS, it's certainly not useful as a
* set-aside OJ clause, even if it's in an OJ.
*/
maybe_outer_join = false;
}
/*
* Build the RestrictInfo node itself.
*/
restrictinfo = make_restrictinfo((Expr *) clause,
is_pushed_down,
outerjoin_delayed,
pseudoconstant,
relids,
outerjoin_nonnullable,
nullable_relids);
/*
* If it's a join clause (either naturally, or because delayed by
* outer-join rules), add vars used in the clause to targetlists of their
* relations, so that they will be emitted by the plan nodes that scan
* those relations (else they won't be available at the join node!).
*
* Note: if the clause gets absorbed into an EquivalenceClass then this
* may be unnecessary, but for now we have to do it to cover the case
* where the EC becomes ec_broken and we end up reinserting the original
* clauses into the plan.
*/
if (bms_membership(relids) == BMS_MULTIPLE)
{
List *vars = pull_var_clause(clause,
PVC_RECURSE_AGGREGATES,
PVC_INCLUDE_PLACEHOLDERS);
add_vars_to_targetlist(root, vars, relids, false);
list_free(vars);
}
/*
* We check "mergejoinability" of every clause, not only join clauses,
* because we want to know about equivalences between vars of the same
* relation, or between vars and consts.
*/
check_mergejoinable(restrictinfo);
/*
* If it is a true equivalence clause, send it to the EquivalenceClass
* machinery. We do *not* attach it directly to any restriction or join
* lists. The EC code will propagate it to the appropriate places later.
*
* If the clause has a mergejoinable operator and is not
* outerjoin-delayed, yet isn't an equivalence because it is an outer-join
* clause, the EC code may yet be able to do something with it. We add it
* to appropriate lists for further consideration later. Specifically:
*
* If it is a left or right outer-join qualification that relates the two
* sides of the outer join (no funny business like leftvar1 = leftvar2 +
* rightvar), we add it to root->left_join_clauses or
* root->right_join_clauses according to which side the nonnullable
* variable appears on.
*
* If it is a full outer-join qualification, we add it to
* root->full_join_clauses. (Ideally we'd discard cases that aren't
* leftvar = rightvar, as we do for left/right joins, but this routine
* doesn't have the info needed to do that; and the current usage of the
* full_join_clauses list doesn't require that, so it's not currently
* worth complicating this routine's API to make it possible.)
*
* If none of the above hold, pass it off to
* distribute_restrictinfo_to_rels().
*
* In all cases, it's important to initialize the left_ec and right_ec
* fields of a mergejoinable clause, so that all possibly mergejoinable
* expressions have representations in EquivalenceClasses. If
* process_equivalence is successful, it will take care of that;
* otherwise, we have to call initialize_mergeclause_eclasses to do it.
*/
if (restrictinfo->mergeopfamilies)
{
if (maybe_equivalence)
{
if (check_equivalence_delay(root, restrictinfo) &&
process_equivalence(root, restrictinfo, below_outer_join))
return;
/* EC rejected it, so set left_ec/right_ec the hard way ... */
initialize_mergeclause_eclasses(root, restrictinfo);
/* ... and fall through to distribute_restrictinfo_to_rels */
}
else if (maybe_outer_join && restrictinfo->can_join)
{
/* we need to set up left_ec/right_ec the hard way */
initialize_mergeclause_eclasses(root, restrictinfo);
/* now see if it should go to any outer-join lists */
if (bms_is_subset(restrictinfo->left_relids,
outerjoin_nonnullable) &&
!bms_overlap(restrictinfo->right_relids,
outerjoin_nonnullable))
{
/* we have outervar = innervar */
root->left_join_clauses = lappend(root->left_join_clauses,
restrictinfo);
return;
}
if (bms_is_subset(restrictinfo->right_relids,
outerjoin_nonnullable) &&
!bms_overlap(restrictinfo->left_relids,
outerjoin_nonnullable))
{
/* we have innervar = outervar */
root->right_join_clauses = lappend(root->right_join_clauses,
restrictinfo);
return;
}
if (jointype == JOIN_FULL)
{
/* FULL JOIN (above tests cannot match in this case) */
root->full_join_clauses = lappend(root->full_join_clauses,
restrictinfo);
return;
}
/* nope, so fall through to distribute_restrictinfo_to_rels */
}
else
{
/* we still need to set up left_ec/right_ec */
initialize_mergeclause_eclasses(root, restrictinfo);
}
}
/* No EC special case applies, so push it into the clause lists */
distribute_restrictinfo_to_rels(root, restrictinfo);
}
| void distribute_restrictinfo_to_rels | ( | PlannerInfo * | root, | |
| RestrictInfo * | restrictinfo | |||
| ) |
Definition at line 1662 of file initsplan.c.
References add_join_clause_to_rels(), RelOptInfo::baserestrictinfo, bms_membership(), BMS_MULTIPLE, BMS_SINGLETON, bms_singleton_member(), check_hashjoinable(), elog, ERROR, find_base_rel(), lappend(), and RestrictInfo::required_relids.
Referenced by distribute_qual_to_rels(), generate_base_implied_equalities_broken(), generate_base_implied_equalities_const(), reconsider_outer_join_clauses(), and remove_rel_from_query().
{
Relids relids = restrictinfo->required_relids;
RelOptInfo *rel;
switch (bms_membership(relids))
{
case BMS_SINGLETON:
/*
* There is only one relation participating in the clause, so it
* is a restriction clause for that relation.
*/
rel = find_base_rel(root, bms_singleton_member(relids));
/* Add clause to rel's restriction list */
rel->baserestrictinfo = lappend(rel->baserestrictinfo,
restrictinfo);
break;
case BMS_MULTIPLE:
/*
* The clause is a join clause, since there is more than one rel
* in its relid set.
*/
/*
* Check for hashjoinable operators. (We don't bother setting the
* hashjoin info except in true join clauses.)
*/
check_hashjoinable(restrictinfo);
/*
* Add clause to the join lists of all the relevant relations.
*/
add_join_clause_to_rels(root, restrictinfo, relids);
break;
default:
/*
* clause references no rels, and therefore we have no place to
* attach it. Shouldn't get here if callers are working properly.
*/
elog(ERROR, "cannot cope with variable-free clause");
break;
}
}
| static void extract_lateral_references | ( | PlannerInfo * | root, | |
| RelOptInfo * | brel, | |||
| Index | rtindex | |||
| ) | [static] |
Definition at line 286 of file initsplan.c.
References add_vars_to_targetlist(), Assert, bms_make_singleton(), copyObject(), RangeTblEntry::funcexpr, IncrementVarSublevelsUp(), IsA, lappend(), RangeTblEntry::lateral, RelOptInfo::lateral_vars, lfirst, list_free(), NIL, PlaceHolderVar::phexpr, PlaceHolderVar::phlevelsup, preprocess_phv_expression(), pull_vars_of_level(), RTE_FUNCTION, RTE_SUBQUERY, RTE_VALUES, RangeTblEntry::rtekind, PlannerInfo::simple_rte_array, RangeTblEntry::subquery, RangeTblEntry::values_lists, RangeQueryClause::var, and Var::varlevelsup.
Referenced by find_lateral_references().
{
RangeTblEntry *rte = root->simple_rte_array[rtindex];
List *vars;
List *newvars;
Relids where_needed;
ListCell *lc;
/* No cross-references are possible if it's not LATERAL */
if (!rte->lateral)
return;
/* Fetch the appropriate variables */
if (rte->rtekind == RTE_SUBQUERY)
vars = pull_vars_of_level((Node *) rte->subquery, 1);
else if (rte->rtekind == RTE_FUNCTION)
vars = pull_vars_of_level(rte->funcexpr, 0);
else if (rte->rtekind == RTE_VALUES)
vars = pull_vars_of_level((Node *) rte->values_lists, 0);
else
{
Assert(false);
return; /* keep compiler quiet */
}
if (vars == NIL)
return; /* nothing to do */
/* Copy each Var (or PlaceHolderVar) and adjust it to match our level */
newvars = NIL;
foreach(lc, vars)
{
Node *node = (Node *) lfirst(lc);
node = copyObject(node);
if (IsA(node, Var))
{
Var *var = (Var *) node;
/* Adjustment is easy since it's just one node */
var->varlevelsup = 0;
}
else if (IsA(node, PlaceHolderVar))
{
PlaceHolderVar *phv = (PlaceHolderVar *) node;
int levelsup = phv->phlevelsup;
/* Have to work harder to adjust the contained expression too */
if (levelsup != 0)
IncrementVarSublevelsUp(node, -levelsup, 0);
/*
* If we pulled the PHV out of a subquery RTE, its expression
* needs to be preprocessed. subquery_planner() already did this
* for level-zero PHVs in function and values RTEs, though.
*/
if (levelsup > 0)
phv->phexpr = preprocess_phv_expression(root, phv->phexpr);
}
else
Assert(false);
newvars = lappend(newvars, node);
}
list_free(vars);
/*
* We mark the Vars as being "needed" at the LATERAL RTE. This is a bit
* of a cheat: a more formal approach would be to mark each one as needed
* at the join of the LATERAL RTE with its source RTE. But it will work,
* and it's much less tedious than computing a separate where_needed for
* each Var.
*/
where_needed = bms_make_singleton(rtindex);
/* Push the Vars into their source relations' targetlists */
add_vars_to_targetlist(root, newvars, where_needed, true);
/* Remember the lateral references for create_lateral_join_info */
brel->lateral_vars = newvars;
}
| void find_lateral_references | ( | PlannerInfo * | root | ) |
Definition at line 240 of file initsplan.c.
References Assert, extract_lateral_references(), PlannerInfo::hasLateralRTEs, NULL, RelOptInfo::relid, RELOPT_BASEREL, RelOptInfo::reloptkind, PlannerInfo::simple_rel_array, and PlannerInfo::simple_rel_array_size.
Referenced by query_planner().
{
Index rti;
/* We need do nothing if the query contains no LATERAL RTEs */
if (!root->hasLateralRTEs)
return;
/*
* Examine all baserels (the rel array has been set up by now).
*/
for (rti = 1; rti < root->simple_rel_array_size; rti++)
{
RelOptInfo *brel = root->simple_rel_array[rti];
/* there may be empty slots corresponding to non-baserel RTEs */
if (brel == NULL)
continue;
Assert(brel->relid == rti); /* sanity check on array */
/*
* This bit is less obvious than it might look. We ignore appendrel
* otherrels and consider only their parent baserels. In a case where
* a LATERAL-containing UNION ALL subquery was pulled up, it is the
* otherrels that are actually going to be in the plan. However, we
* want to mark all their lateral references as needed by the parent,
* because it is the parent's relid that will be used for join
* planning purposes. And the parent's RTE will contain all the
* lateral references we need to know, since the pulled-up members are
* nothing but copies of parts of the original RTE's subquery. We
* could visit the children instead and transform their references
* back to the parent's relid, but it would be much more complicated
* for no real gain. (Important here is that the child members have
* not yet received any processing beyond being pulled up.)
*/
/* ignore RTEs that are "other rels" */
if (brel->reloptkind != RELOPT_BASEREL)
continue;
extract_lateral_references(root, brel, rti);
}
}
| static SpecialJoinInfo * make_outerjoininfo | ( | PlannerInfo * | root, | |
| Relids | left_rels, | |||
| Relids | right_rels, | |||
| Relids | inner_join_rels, | |||
| JoinType | jointype, | |||
| List * | clause | |||
| ) | [static] |
Definition at line 844 of file initsplan.c.
References Assert, bms_add_members(), bms_copy(), bms_int_members(), bms_intersect(), bms_is_empty(), bms_is_member(), bms_is_subset(), bms_overlap(), bms_union(), SpecialJoinInfo::delay_upper_joins, ereport, errcode(), errmsg(), ERROR, find_nonnullable_rels(), JOIN_ANTI, JOIN_FULL, PlannerInfo::join_info_list, JOIN_INNER, SpecialJoinInfo::join_quals, JOIN_RIGHT, JOIN_SEMI, SpecialJoinInfo::jointype, lfirst, SpecialJoinInfo::lhs_strict, makeNode, SpecialJoinInfo::min_lefthand, SpecialJoinInfo::min_righthand, PlannerInfo::parse, PlaceHolderInfo::ph_eval_at, PlaceHolderInfo::ph_may_need, PlaceHolderInfo::ph_var, PlaceHolderVar::phrels, PlannerInfo::placeholder_list, pull_varnos(), Query::rowMarks, RowMarkClause::rti, SpecialJoinInfo::syn_lefthand, and SpecialJoinInfo::syn_righthand.
Referenced by deconstruct_recurse().
{
SpecialJoinInfo *sjinfo = makeNode(SpecialJoinInfo);
Relids clause_relids;
Relids strict_relids;
Relids min_lefthand;
Relids min_righthand;
ListCell *l;
/*
* We should not see RIGHT JOIN here because left/right were switched
* earlier
*/
Assert(jointype != JOIN_INNER);
Assert(jointype != JOIN_RIGHT);
/*
* Presently the executor cannot support FOR [KEY] UPDATE/SHARE marking of rels
* appearing on the nullable side of an outer join. (It's somewhat unclear
* what that would mean, anyway: what should we mark when a result row is
* generated from no element of the nullable relation?) So, complain if
* any nullable rel is FOR [KEY] UPDATE/SHARE.
*
* You might be wondering why this test isn't made far upstream in the
* parser. It's because the parser hasn't got enough info --- consider
* FOR UPDATE applied to a view. Only after rewriting and flattening do
* we know whether the view contains an outer join.
*
* We use the original RowMarkClause list here; the PlanRowMark list would
* list everything.
*/
foreach(l, root->parse->rowMarks)
{
RowMarkClause *rc = (RowMarkClause *) lfirst(l);
if (bms_is_member(rc->rti, right_rels) ||
(jointype == JOIN_FULL && bms_is_member(rc->rti, left_rels)))
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("row-level locks cannot be applied to the nullable side of an outer join")));
}
sjinfo->syn_lefthand = left_rels;
sjinfo->syn_righthand = right_rels;
sjinfo->jointype = jointype;
/* this always starts out false */
sjinfo->delay_upper_joins = false;
sjinfo->join_quals = clause;
/* If it's a full join, no need to be very smart */
if (jointype == JOIN_FULL)
{
sjinfo->min_lefthand = bms_copy(left_rels);
sjinfo->min_righthand = bms_copy(right_rels);
sjinfo->lhs_strict = false; /* don't care about this */
return sjinfo;
}
/*
* Retrieve all relids mentioned within the join clause.
*/
clause_relids = pull_varnos((Node *) clause);
/*
* For which relids is the clause strict, ie, it cannot succeed if the
* rel's columns are all NULL?
*/
strict_relids = find_nonnullable_rels((Node *) clause);
/* Remember whether the clause is strict for any LHS relations */
sjinfo->lhs_strict = bms_overlap(strict_relids, left_rels);
/*
* Required LHS always includes the LHS rels mentioned in the clause. We
* may have to add more rels based on lower outer joins; see below.
*/
min_lefthand = bms_intersect(clause_relids, left_rels);
/*
* Similarly for required RHS. But here, we must also include any lower
* inner joins, to ensure we don't try to commute with any of them.
*/
min_righthand = bms_int_members(bms_union(clause_relids, inner_join_rels),
right_rels);
foreach(l, root->join_info_list)
{
SpecialJoinInfo *otherinfo = (SpecialJoinInfo *) lfirst(l);
/* ignore full joins --- other mechanisms preserve their ordering */
if (otherinfo->jointype == JOIN_FULL)
continue;
/*
* For a lower OJ in our LHS, if our join condition uses the lower
* join's RHS and is not strict for that rel, we must preserve the
* ordering of the two OJs, so add lower OJ's full syntactic relset to
* min_lefthand. (We must use its full syntactic relset, not just its
* min_lefthand + min_righthand. This is because there might be other
* OJs below this one that this one can commute with, but we cannot
* commute with them if we don't with this one.) Also, if the current
* join is a semijoin or antijoin, we must preserve ordering
* regardless of strictness.
*
* Note: I believe we have to insist on being strict for at least one
* rel in the lower OJ's min_righthand, not its whole syn_righthand.
*/
if (bms_overlap(left_rels, otherinfo->syn_righthand))
{
if (bms_overlap(clause_relids, otherinfo->syn_righthand) &&
(jointype == JOIN_SEMI || jointype == JOIN_ANTI ||
!bms_overlap(strict_relids, otherinfo->min_righthand)))
{
min_lefthand = bms_add_members(min_lefthand,
otherinfo->syn_lefthand);
min_lefthand = bms_add_members(min_lefthand,
otherinfo->syn_righthand);
}
}
/*
* For a lower OJ in our RHS, if our join condition does not use the
* lower join's RHS and the lower OJ's join condition is strict, we
* can interchange the ordering of the two OJs; otherwise we must add
* lower OJ's full syntactic relset to min_righthand. Here, we must
* preserve ordering anyway if either the current join is a semijoin,
* or the lower OJ is either a semijoin or an antijoin.
*
* Here, we have to consider that "our join condition" includes any
* clauses that syntactically appeared above the lower OJ and below
* ours; those are equivalent to degenerate clauses in our OJ and must
* be treated as such. Such clauses obviously can't reference our
* LHS, and they must be non-strict for the lower OJ's RHS (else
* reduce_outer_joins would have reduced the lower OJ to a plain
* join). Hence the other ways in which we handle clauses within our
* join condition are not affected by them. The net effect is
* therefore sufficiently represented by the delay_upper_joins flag
* saved for us by check_outerjoin_delay.
*/
if (bms_overlap(right_rels, otherinfo->syn_righthand))
{
if (bms_overlap(clause_relids, otherinfo->syn_righthand) ||
jointype == JOIN_SEMI ||
otherinfo->jointype == JOIN_SEMI ||
otherinfo->jointype == JOIN_ANTI ||
!otherinfo->lhs_strict || otherinfo->delay_upper_joins)
{
min_righthand = bms_add_members(min_righthand,
otherinfo->syn_lefthand);
min_righthand = bms_add_members(min_righthand,
otherinfo->syn_righthand);
}
}
}
/*
* Examine PlaceHolderVars. If a PHV is supposed to be evaluated within
* this join's nullable side, and it may get used above this join, then
* ensure that min_righthand contains the full eval_at set of the PHV.
* This ensures that the PHV actually can be evaluated within the RHS.
* Note that this works only because we should already have determined the
* final eval_at level for any PHV syntactically within this join.
*/
foreach(l, root->placeholder_list)
{
PlaceHolderInfo *phinfo = (PlaceHolderInfo *) lfirst(l);
Relids ph_syn_level = phinfo->ph_var->phrels;
/* Ignore placeholder if it didn't syntactically come from RHS */
if (!bms_is_subset(ph_syn_level, right_rels))
continue;
/* We can also ignore it if it's certainly not used above this join */
/* XXX this test is probably overly conservative */
if (bms_is_subset(phinfo->ph_may_need, min_righthand))
continue;
/* Else, prevent join from being formed before we eval the PHV */
min_righthand = bms_add_members(min_righthand, phinfo->ph_eval_at);
}
/*
* If we found nothing to put in min_lefthand, punt and make it the full
* LHS, to avoid having an empty min_lefthand which will confuse later
* processing. (We don't try to be smart about such cases, just correct.)
* Likewise for min_righthand.
*/
if (bms_is_empty(min_lefthand))
min_lefthand = bms_copy(left_rels);
if (bms_is_empty(min_righthand))
min_righthand = bms_copy(right_rels);
/* Now they'd better be nonempty */
Assert(!bms_is_empty(min_lefthand));
Assert(!bms_is_empty(min_righthand));
/* Shouldn't overlap either */
Assert(!bms_overlap(min_lefthand, min_righthand));
sjinfo->min_lefthand = min_lefthand;
sjinfo->min_righthand = min_righthand;
return sjinfo;
}
| void process_implied_equality | ( | PlannerInfo * | root, | |
| Oid | opno, | |||
| Oid | collation, | |||
| Expr * | item1, | |||
| Expr * | item2, | |||
| Relids | qualscope, | |||
| Relids | nullable_relids, | |||
| bool | below_outer_join, | |||
| bool | both_const | |||
| ) |
Definition at line 1741 of file initsplan.c.
References Assert, BOOLOID, Const::constisnull, Const::consttype, Const::constvalue, copyObject(), DatumGetBool, distribute_qual_to_rels(), eval_const_expressions(), InvalidOid, IsA, JOIN_INNER, make_opclause(), and NULL.
Referenced by generate_base_implied_equalities_const(), and generate_base_implied_equalities_no_const().
{
Expr *clause;
/*
* Build the new clause. Copy to ensure it shares no substructure with
* original (this is necessary in case there are subselects in there...)
*/
clause = make_opclause(opno,
BOOLOID, /* opresulttype */
false, /* opretset */
(Expr *) copyObject(item1),
(Expr *) copyObject(item2),
InvalidOid,
collation);
/* If both constant, try to reduce to a boolean constant. */
if (both_const)
{
clause = (Expr *) eval_const_expressions(root, (Node *) clause);
/* If we produced const TRUE, just drop the clause */
if (clause && IsA(clause, Const))
{
Const *cclause = (Const *) clause;
Assert(cclause->consttype == BOOLOID);
if (!cclause->constisnull && DatumGetBool(cclause->constvalue))
return;
}
}
/*
* Push the new clause into all the appropriate restrictinfo lists.
*/
distribute_qual_to_rels(root, (Node *) clause,
true, below_outer_join, JOIN_INNER,
qualscope, NULL, NULL, nullable_relids);
}
Definition at line 34 of file initsplan.c.
Referenced by deconstruct_recurse().
Definition at line 35 of file initsplan.c.
Referenced by deconstruct_recurse().
1.7.1