PostgreSQL Source Code git master
equivclass.c File Reference
#include "postgres.h"
#include <limits.h>
#include "access/stratnum.h"
#include "catalog/pg_type.h"
#include "nodes/makefuncs.h"
#include "nodes/nodeFuncs.h"
#include "optimizer/appendinfo.h"
#include "optimizer/clauses.h"
#include "optimizer/optimizer.h"
#include "optimizer/pathnode.h"
#include "optimizer/paths.h"
#include "optimizer/planmain.h"
#include "optimizer/restrictinfo.h"
#include "rewrite/rewriteManip.h"
#include "utils/lsyscache.h"
Include dependency graph for equivclass.c:

Go to the source code of this file.

Functions

static EquivalenceMemberadd_eq_member (EquivalenceClass *ec, Expr *expr, Relids relids, JoinDomain *jdomain, EquivalenceMember *parent, Oid datatype)
 
static void generate_base_implied_equalities_const (PlannerInfo *root, EquivalenceClass *ec)
 
static void generate_base_implied_equalities_no_const (PlannerInfo *root, EquivalenceClass *ec)
 
static void generate_base_implied_equalities_broken (PlannerInfo *root, EquivalenceClass *ec)
 
static Listgenerate_join_implied_equalities_normal (PlannerInfo *root, EquivalenceClass *ec, Relids join_relids, Relids outer_relids, Relids inner_relids)
 
static Listgenerate_join_implied_equalities_broken (PlannerInfo *root, EquivalenceClass *ec, Relids nominal_join_relids, Relids outer_relids, Relids nominal_inner_relids, RelOptInfo *inner_rel)
 
static Oid select_equality_operator (EquivalenceClass *ec, Oid lefttype, Oid righttype)
 
static RestrictInfocreate_join_clause (PlannerInfo *root, EquivalenceClass *ec, Oid opno, EquivalenceMember *leftem, EquivalenceMember *rightem, EquivalenceClass *parent_ec)
 
static bool reconsider_outer_join_clause (PlannerInfo *root, OuterJoinClauseInfo *ojcinfo, bool outer_on_left)
 
static bool reconsider_full_join_clause (PlannerInfo *root, OuterJoinClauseInfo *ojcinfo)
 
static JoinDomainfind_join_domain (PlannerInfo *root, Relids relids)
 
static Bitmapsetget_eclass_indexes_for_relids (PlannerInfo *root, Relids relids)
 
static Bitmapsetget_common_eclass_indexes (PlannerInfo *root, Relids relids1, Relids relids2)
 
bool process_equivalence (PlannerInfo *root, RestrictInfo **p_restrictinfo, JoinDomain *jdomain)
 
Exprcanonicalize_ec_expression (Expr *expr, Oid req_type, Oid req_collation)
 
EquivalenceClassget_eclass_for_sort_expr (PlannerInfo *root, Expr *expr, List *opfamilies, Oid opcintype, Oid collation, Index sortref, Relids rel, bool create_it)
 
EquivalenceMemberfind_ec_member_matching_expr (EquivalenceClass *ec, Expr *expr, Relids relids)
 
EquivalenceMemberfind_computable_ec_member (PlannerInfo *root, EquivalenceClass *ec, List *exprs, Relids relids, bool require_parallel_safe)
 
bool relation_can_be_sorted_early (PlannerInfo *root, RelOptInfo *rel, EquivalenceClass *ec, bool require_parallel_safe)
 
void generate_base_implied_equalities (PlannerInfo *root)
 
Listgenerate_join_implied_equalities (PlannerInfo *root, Relids join_relids, Relids outer_relids, RelOptInfo *inner_rel, SpecialJoinInfo *sjinfo)
 
Listgenerate_join_implied_equalities_for_ecs (PlannerInfo *root, List *eclasses, Relids join_relids, Relids outer_relids, RelOptInfo *inner_rel)
 
void reconsider_outer_join_clauses (PlannerInfo *root)
 
void rebuild_eclass_attr_needed (PlannerInfo *root)
 
bool exprs_known_equal (PlannerInfo *root, Node *item1, Node *item2, Oid opfamily)
 
EquivalenceClassmatch_eclasses_to_foreign_key_col (PlannerInfo *root, ForeignKeyOptInfo *fkinfo, int colno)
 
RestrictInfofind_derived_clause_for_ec_member (EquivalenceClass *ec, EquivalenceMember *em)
 
void add_child_rel_equivalences (PlannerInfo *root, AppendRelInfo *appinfo, RelOptInfo *parent_rel, RelOptInfo *child_rel)
 
void add_child_join_rel_equivalences (PlannerInfo *root, int nappinfos, AppendRelInfo **appinfos, RelOptInfo *parent_joinrel, RelOptInfo *child_joinrel)
 
void add_setop_child_rel_equivalences (PlannerInfo *root, RelOptInfo *child_rel, List *child_tlist, List *setop_pathkeys)
 
Listgenerate_implied_equalities_for_column (PlannerInfo *root, RelOptInfo *rel, ec_matches_callback_type callback, void *callback_arg, Relids prohibited_rels)
 
bool have_relevant_eclass_joinclause (PlannerInfo *root, RelOptInfo *rel1, RelOptInfo *rel2)
 
bool has_relevant_eclass_joinclause (PlannerInfo *root, RelOptInfo *rel1)
 
bool eclass_useful_for_merging (PlannerInfo *root, EquivalenceClass *eclass, RelOptInfo *rel)
 
bool is_redundant_derived_clause (RestrictInfo *rinfo, List *clauselist)
 
bool is_redundant_with_indexclauses (RestrictInfo *rinfo, List *indexclauses)
 

Function Documentation

◆ add_child_join_rel_equivalences()

void add_child_join_rel_equivalences ( PlannerInfo root,
int  nappinfos,
AppendRelInfo **  appinfos,
RelOptInfo parent_joinrel,
RelOptInfo child_joinrel 
)

Definition at line 2812 of file equivclass.c.

2816{
2817 Relids top_parent_relids = child_joinrel->top_parent_relids;
2818 Relids child_relids = child_joinrel->relids;
2819 Bitmapset *matching_ecs;
2820 MemoryContext oldcontext;
2821 int i;
2822
2823 Assert(IS_JOIN_REL(child_joinrel) && IS_JOIN_REL(parent_joinrel));
2824
2825 /* We need consider only ECs that mention the parent joinrel */
2826 matching_ecs = get_eclass_indexes_for_relids(root, top_parent_relids);
2827
2828 /*
2829 * If we're being called during GEQO join planning, we still have to
2830 * create any new EC members in the main planner context, to avoid having
2831 * a corrupt EC data structure after the GEQO context is reset. This is
2832 * problematic since we'll leak memory across repeated GEQO cycles. For
2833 * now, though, bloat is better than crash. If it becomes a real issue
2834 * we'll have to do something to avoid generating duplicate EC members.
2835 */
2836 oldcontext = MemoryContextSwitchTo(root->planner_cxt);
2837
2838 i = -1;
2839 while ((i = bms_next_member(matching_ecs, i)) >= 0)
2840 {
2841 EquivalenceClass *cur_ec = (EquivalenceClass *) list_nth(root->eq_classes, i);
2842 int num_members;
2843
2844 /*
2845 * If this EC contains a volatile expression, then generating child
2846 * EMs would be downright dangerous, so skip it. We rely on a
2847 * volatile EC having only one EM.
2848 */
2849 if (cur_ec->ec_has_volatile)
2850 continue;
2851
2852 /* Sanity check on get_eclass_indexes_for_relids result */
2853 Assert(bms_overlap(top_parent_relids, cur_ec->ec_relids));
2854
2855 /*
2856 * We don't use foreach() here because there's no point in scanning
2857 * newly-added child members, so we can stop after the last
2858 * pre-existing EC member.
2859 */
2860 num_members = list_length(cur_ec->ec_members);
2861 for (int pos = 0; pos < num_members; pos++)
2862 {
2863 EquivalenceMember *cur_em = (EquivalenceMember *) list_nth(cur_ec->ec_members, pos);
2864
2865 if (cur_em->em_is_const)
2866 continue; /* ignore consts here */
2867
2868 /*
2869 * We consider only original EC members here, not
2870 * already-transformed child members.
2871 */
2872 if (cur_em->em_is_child)
2873 continue; /* ignore children here */
2874
2875 /*
2876 * We may ignore expressions that reference a single baserel,
2877 * because add_child_rel_equivalences should have handled them.
2878 */
2879 if (bms_membership(cur_em->em_relids) != BMS_MULTIPLE)
2880 continue;
2881
2882 /* Does this member reference child's topmost parent rel? */
2883 if (bms_overlap(cur_em->em_relids, top_parent_relids))
2884 {
2885 /* Yes, generate transformed child version */
2886 Expr *child_expr;
2887 Relids new_relids;
2888
2889 if (parent_joinrel->reloptkind == RELOPT_JOINREL)
2890 {
2891 /* Simple single-level transformation */
2892 child_expr = (Expr *)
2894 (Node *) cur_em->em_expr,
2895 nappinfos, appinfos);
2896 }
2897 else
2898 {
2899 /* Must do multi-level transformation */
2900 Assert(parent_joinrel->reloptkind == RELOPT_OTHER_JOINREL);
2901 child_expr = (Expr *)
2903 (Node *) cur_em->em_expr,
2904 child_joinrel,
2905 child_joinrel->top_parent);
2906 }
2907
2908 /*
2909 * Transform em_relids to match. Note we do *not* do
2910 * pull_varnos(child_expr) here, as for example the
2911 * transformation might have substituted a constant, but we
2912 * don't want the child member to be marked as constant.
2913 */
2914 new_relids = bms_difference(cur_em->em_relids,
2915 top_parent_relids);
2916 new_relids = bms_add_members(new_relids, child_relids);
2917
2918 (void) add_eq_member(cur_ec, child_expr, new_relids,
2919 cur_em->em_jdomain,
2920 cur_em, cur_em->em_datatype);
2921 }
2922 }
2923 }
2924
2925 MemoryContextSwitchTo(oldcontext);
2926}
Node * adjust_appendrel_attrs(PlannerInfo *root, Node *node, int nappinfos, AppendRelInfo **appinfos)
Definition: appendinfo.c:200
Node * adjust_appendrel_attrs_multilevel(PlannerInfo *root, Node *node, RelOptInfo *childrel, RelOptInfo *parentrel)
Definition: appendinfo.c:541
Bitmapset * bms_difference(const Bitmapset *a, const Bitmapset *b)
Definition: bitmapset.c:346
int bms_next_member(const Bitmapset *a, int prevbit)
Definition: bitmapset.c:1306
Bitmapset * bms_add_members(Bitmapset *a, const Bitmapset *b)
Definition: bitmapset.c:917
BMS_Membership bms_membership(const Bitmapset *a)
Definition: bitmapset.c:781
bool bms_overlap(const Bitmapset *a, const Bitmapset *b)
Definition: bitmapset.c:582
@ BMS_MULTIPLE
Definition: bitmapset.h:73
#define Assert(condition)
Definition: c.h:815
static EquivalenceMember * add_eq_member(EquivalenceClass *ec, Expr *expr, Relids relids, JoinDomain *jdomain, EquivalenceMember *parent, Oid datatype)
Definition: equivclass.c:516
static Bitmapset * get_eclass_indexes_for_relids(PlannerInfo *root, Relids relids)
Definition: equivclass.c:3387
int i
Definition: isn.c:72
static MemoryContext MemoryContextSwitchTo(MemoryContext context)
Definition: palloc.h:124
#define IS_JOIN_REL(rel)
Definition: pathnodes.h:863
@ RELOPT_JOINREL
Definition: pathnodes.h:847
@ RELOPT_OTHER_JOINREL
Definition: pathnodes.h:849
static int list_length(const List *l)
Definition: pg_list.h:152
static void * list_nth(const List *list, int n)
Definition: pg_list.h:299
tree ctl root
Definition: radixtree.h:1857
JoinDomain * em_jdomain
Definition: pathnodes.h:1469
Definition: nodes.h:129
Relids relids
Definition: pathnodes.h:890
Relids top_parent_relids
Definition: pathnodes.h:1028
RelOptKind reloptkind
Definition: pathnodes.h:884

References add_eq_member(), adjust_appendrel_attrs(), adjust_appendrel_attrs_multilevel(), Assert, bms_add_members(), bms_difference(), bms_membership(), BMS_MULTIPLE, bms_next_member(), bms_overlap(), EquivalenceClass::ec_has_volatile, EquivalenceClass::ec_members, EquivalenceClass::ec_relids, EquivalenceMember::em_datatype, EquivalenceMember::em_expr, EquivalenceMember::em_is_child, EquivalenceMember::em_is_const, EquivalenceMember::em_jdomain, EquivalenceMember::em_relids, get_eclass_indexes_for_relids(), i, IS_JOIN_REL, list_length(), list_nth(), MemoryContextSwitchTo(), RelOptInfo::relids, RELOPT_JOINREL, RELOPT_OTHER_JOINREL, RelOptInfo::reloptkind, root, and RelOptInfo::top_parent_relids.

Referenced by build_child_join_rel().

◆ add_child_rel_equivalences()

void add_child_rel_equivalences ( PlannerInfo root,
AppendRelInfo appinfo,
RelOptInfo parent_rel,
RelOptInfo child_rel 
)

Definition at line 2690 of file equivclass.c.

2694{
2695 Relids top_parent_relids = child_rel->top_parent_relids;
2696 Relids child_relids = child_rel->relids;
2697 int i;
2698
2699 /*
2700 * EC merging should be complete already, so we can use the parent rel's
2701 * eclass_indexes to avoid searching all of root->eq_classes.
2702 */
2703 Assert(root->ec_merging_done);
2704 Assert(IS_SIMPLE_REL(parent_rel));
2705
2706 i = -1;
2707 while ((i = bms_next_member(parent_rel->eclass_indexes, i)) >= 0)
2708 {
2709 EquivalenceClass *cur_ec = (EquivalenceClass *) list_nth(root->eq_classes, i);
2710 int num_members;
2711
2712 /*
2713 * If this EC contains a volatile expression, then generating child
2714 * EMs would be downright dangerous, so skip it. We rely on a
2715 * volatile EC having only one EM.
2716 */
2717 if (cur_ec->ec_has_volatile)
2718 continue;
2719
2720 /* Sanity check eclass_indexes only contain ECs for parent_rel */
2721 Assert(bms_is_subset(top_parent_relids, cur_ec->ec_relids));
2722
2723 /*
2724 * We don't use foreach() here because there's no point in scanning
2725 * newly-added child members, so we can stop after the last
2726 * pre-existing EC member.
2727 */
2728 num_members = list_length(cur_ec->ec_members);
2729 for (int pos = 0; pos < num_members; pos++)
2730 {
2731 EquivalenceMember *cur_em = (EquivalenceMember *) list_nth(cur_ec->ec_members, pos);
2732
2733 if (cur_em->em_is_const)
2734 continue; /* ignore consts here */
2735
2736 /*
2737 * We consider only original EC members here, not
2738 * already-transformed child members. Otherwise, if some original
2739 * member expression references more than one appendrel, we'd get
2740 * an O(N^2) explosion of useless derived expressions for
2741 * combinations of children. (But add_child_join_rel_equivalences
2742 * may add targeted combinations for partitionwise-join purposes.)
2743 */
2744 if (cur_em->em_is_child)
2745 continue; /* ignore children here */
2746
2747 /*
2748 * Consider only members that reference and can be computed at
2749 * child's topmost parent rel. In particular we want to exclude
2750 * parent-rel Vars that have nonempty varnullingrels. Translating
2751 * those might fail, if the transformed expression wouldn't be a
2752 * simple Var; and in any case it wouldn't produce a member that
2753 * has any use in creating plans for the child rel.
2754 */
2755 if (bms_is_subset(cur_em->em_relids, top_parent_relids) &&
2756 !bms_is_empty(cur_em->em_relids))
2757 {
2758 /* OK, generate transformed child version */
2759 Expr *child_expr;
2760 Relids new_relids;
2761
2762 if (parent_rel->reloptkind == RELOPT_BASEREL)
2763 {
2764 /* Simple single-level transformation */
2765 child_expr = (Expr *)
2767 (Node *) cur_em->em_expr,
2768 1, &appinfo);
2769 }
2770 else
2771 {
2772 /* Must do multi-level transformation */
2773 child_expr = (Expr *)
2775 (Node *) cur_em->em_expr,
2776 child_rel,
2777 child_rel->top_parent);
2778 }
2779
2780 /*
2781 * Transform em_relids to match. Note we do *not* do
2782 * pull_varnos(child_expr) here, as for example the
2783 * transformation might have substituted a constant, but we
2784 * don't want the child member to be marked as constant.
2785 */
2786 new_relids = bms_difference(cur_em->em_relids,
2787 top_parent_relids);
2788 new_relids = bms_add_members(new_relids, child_relids);
2789
2790 (void) add_eq_member(cur_ec, child_expr, new_relids,
2791 cur_em->em_jdomain,
2792 cur_em, cur_em->em_datatype);
2793
2794 /* Record this EC index for the child rel */
2795 child_rel->eclass_indexes = bms_add_member(child_rel->eclass_indexes, i);
2796 }
2797 }
2798 }
2799}
bool bms_is_subset(const Bitmapset *a, const Bitmapset *b)
Definition: bitmapset.c:412
Bitmapset * bms_add_member(Bitmapset *a, int x)
Definition: bitmapset.c:815
#define bms_is_empty(a)
Definition: bitmapset.h:118
#define IS_SIMPLE_REL(rel)
Definition: pathnodes.h:858
@ RELOPT_BASEREL
Definition: pathnodes.h:846
Bitmapset * eclass_indexes
Definition: pathnodes.h:971

References add_eq_member(), adjust_appendrel_attrs(), adjust_appendrel_attrs_multilevel(), Assert, bms_add_member(), bms_add_members(), bms_difference(), bms_is_empty, bms_is_subset(), bms_next_member(), EquivalenceClass::ec_has_volatile, EquivalenceClass::ec_members, EquivalenceClass::ec_relids, RelOptInfo::eclass_indexes, EquivalenceMember::em_datatype, EquivalenceMember::em_expr, EquivalenceMember::em_is_child, EquivalenceMember::em_is_const, EquivalenceMember::em_jdomain, EquivalenceMember::em_relids, i, IS_SIMPLE_REL, list_length(), list_nth(), RelOptInfo::relids, RELOPT_BASEREL, RelOptInfo::reloptkind, root, and RelOptInfo::top_parent_relids.

Referenced by set_append_rel_size().

◆ add_eq_member()

static EquivalenceMember * add_eq_member ( EquivalenceClass ec,
Expr expr,
Relids  relids,
JoinDomain jdomain,
EquivalenceMember parent,
Oid  datatype 
)
static

Definition at line 516 of file equivclass.c.

518{
520
521 em->em_expr = expr;
522 em->em_relids = relids;
523 em->em_is_const = false;
524 em->em_is_child = (parent != NULL);
525 em->em_datatype = datatype;
526 em->em_jdomain = jdomain;
527 em->em_parent = parent;
528
529 if (bms_is_empty(relids))
530 {
531 /*
532 * No Vars, assume it's a pseudoconstant. This is correct for entries
533 * generated from process_equivalence(), because a WHERE clause can't
534 * contain aggregates or SRFs, and non-volatility was checked before
535 * process_equivalence() ever got called. But
536 * get_eclass_for_sort_expr() has to work harder. We put the tests
537 * there not here to save cycles in the equivalence case.
538 */
539 Assert(!parent);
540 em->em_is_const = true;
541 ec->ec_has_const = true;
542 /* it can't affect ec_relids */
543 }
544 else if (!parent) /* child members don't add to ec_relids */
545 {
546 ec->ec_relids = bms_add_members(ec->ec_relids, relids);
547 }
548 ec->ec_members = lappend(ec->ec_members, em);
549
550 return em;
551}
List * lappend(List *list, void *datum)
Definition: list.c:339
#define makeNode(_type_)
Definition: nodes.h:155

References Assert, bms_add_members(), bms_is_empty, EquivalenceClass::ec_has_const, EquivalenceClass::ec_members, EquivalenceClass::ec_relids, EquivalenceMember::em_datatype, EquivalenceMember::em_expr, EquivalenceMember::em_is_child, EquivalenceMember::em_is_const, EquivalenceMember::em_jdomain, EquivalenceMember::em_relids, lappend(), and makeNode.

Referenced by add_child_join_rel_equivalences(), add_child_rel_equivalences(), add_setop_child_rel_equivalences(), get_eclass_for_sort_expr(), and process_equivalence().

◆ add_setop_child_rel_equivalences()

void add_setop_child_rel_equivalences ( PlannerInfo root,
RelOptInfo child_rel,
List child_tlist,
List setop_pathkeys 
)

Definition at line 2942 of file equivclass.c.

2944{
2945 ListCell *lc;
2946 ListCell *lc2 = list_head(setop_pathkeys);
2947
2948 foreach(lc, child_tlist)
2949 {
2951 EquivalenceMember *parent_em;
2952 PathKey *pk;
2953
2954 if (tle->resjunk)
2955 continue;
2956
2957 if (lc2 == NULL)
2958 elog(ERROR, "too few pathkeys for set operation");
2959
2960 pk = lfirst_node(PathKey, lc2);
2961 parent_em = linitial(pk->pk_eclass->ec_members);
2962
2963 /*
2964 * We can safely pass the parent member as the first member in the
2965 * ec_members list as this is added first in generate_union_paths,
2966 * likewise, the JoinDomain can be that of the initial member of the
2967 * Pathkey's EquivalenceClass.
2968 */
2969 add_eq_member(pk->pk_eclass,
2970 tle->expr,
2971 child_rel->relids,
2972 parent_em->em_jdomain,
2973 parent_em,
2974 exprType((Node *) tle->expr));
2975
2976 lc2 = lnext(setop_pathkeys, lc2);
2977 }
2978
2979 /*
2980 * transformSetOperationStmt() ensures that the targetlist never contains
2981 * any resjunk columns, so all eclasses that exist in 'root' must have
2982 * received a new member in the loop above. Add them to the child_rel's
2983 * eclass_indexes.
2984 */
2985 child_rel->eclass_indexes = bms_add_range(child_rel->eclass_indexes, 0,
2986 list_length(root->eq_classes) - 1);
2987}
Bitmapset * bms_add_range(Bitmapset *a, int lower, int upper)
Definition: bitmapset.c:1019
#define ERROR
Definition: elog.h:39
#define elog(elevel,...)
Definition: elog.h:225
Oid exprType(const Node *expr)
Definition: nodeFuncs.c:42
#define lfirst_node(type, lc)
Definition: pg_list.h:176
#define linitial(l)
Definition: pg_list.h:178
static ListCell * list_head(const List *l)
Definition: pg_list.h:128
static ListCell * lnext(const List *l, const ListCell *c)
Definition: pg_list.h:343
Expr * expr
Definition: primnodes.h:2219

References add_eq_member(), bms_add_range(), RelOptInfo::eclass_indexes, elog, EquivalenceMember::em_jdomain, ERROR, TargetEntry::expr, exprType(), lfirst_node, linitial, list_head(), list_length(), lnext(), RelOptInfo::relids, and root.

Referenced by build_setop_child_paths().

◆ canonicalize_ec_expression()

Expr * canonicalize_ec_expression ( Expr expr,
Oid  req_type,
Oid  req_collation 
)

Definition at line 471 of file equivclass.c.

472{
473 Oid expr_type = exprType((Node *) expr);
474
475 /*
476 * For a polymorphic-input-type opclass, just keep the same exposed type.
477 * RECORD opclasses work like polymorphic-type ones for this purpose.
478 */
479 if (IsPolymorphicType(req_type) || req_type == RECORDOID)
480 req_type = expr_type;
481
482 /*
483 * No work if the expression exposes the right type/collation already.
484 */
485 if (expr_type != req_type ||
486 exprCollation((Node *) expr) != req_collation)
487 {
488 /*
489 * If we have to change the type of the expression, set typmod to -1,
490 * since the new type may not have the same typmod interpretation.
491 * When we only have to change collation, preserve the exposed typmod.
492 */
493 int32 req_typmod;
494
495 if (expr_type != req_type)
496 req_typmod = -1;
497 else
498 req_typmod = exprTypmod((Node *) expr);
499
500 /*
501 * Use applyRelabelType so that we preserve const-flatness. This is
502 * important since eval_const_expressions has already been applied.
503 */
504 expr = (Expr *) applyRelabelType((Node *) expr,
505 req_type, req_typmod, req_collation,
506 COERCE_IMPLICIT_CAST, -1, false);
507 }
508
509 return expr;
510}
int32_t int32
Definition: c.h:484
int32 exprTypmod(const Node *expr)
Definition: nodeFuncs.c:301
Oid exprCollation(const Node *expr)
Definition: nodeFuncs.c:821
Node * applyRelabelType(Node *arg, Oid rtype, int32 rtypmod, Oid rcollid, CoercionForm rformat, int rlocation, bool overwrite_ok)
Definition: nodeFuncs.c:636
unsigned int Oid
Definition: postgres_ext.h:32
@ COERCE_IMPLICIT_CAST
Definition: primnodes.h:753

References applyRelabelType(), COERCE_IMPLICIT_CAST, exprCollation(), exprType(), and exprTypmod().

Referenced by convert_subquery_pathkeys(), get_eclass_for_sort_expr(), and process_equivalence().

◆ create_join_clause()

static RestrictInfo * create_join_clause ( PlannerInfo root,
EquivalenceClass ec,
Oid  opno,
EquivalenceMember leftem,
EquivalenceMember rightem,
EquivalenceClass parent_ec 
)
static

Definition at line 1817 of file equivclass.c.

1822{
1823 RestrictInfo *rinfo;
1824 RestrictInfo *parent_rinfo = NULL;
1825 ListCell *lc;
1826 MemoryContext oldcontext;
1827
1828 /*
1829 * Search to see if we already built a RestrictInfo for this pair of
1830 * EquivalenceMembers. We can use either original source clauses or
1831 * previously-derived clauses, and a commutator clause is acceptable.
1832 *
1833 * We used to verify that opno matches, but that seems redundant: even if
1834 * it's not identical, it'd better have the same effects, or the operator
1835 * families we're using are broken.
1836 */
1837 foreach(lc, ec->ec_sources)
1838 {
1839 rinfo = (RestrictInfo *) lfirst(lc);
1840 if (rinfo->left_em == leftem &&
1841 rinfo->right_em == rightem &&
1842 rinfo->parent_ec == parent_ec)
1843 return rinfo;
1844 if (rinfo->left_em == rightem &&
1845 rinfo->right_em == leftem &&
1846 rinfo->parent_ec == parent_ec)
1847 return rinfo;
1848 }
1849
1850 foreach(lc, ec->ec_derives)
1851 {
1852 rinfo = (RestrictInfo *) lfirst(lc);
1853 if (rinfo->left_em == leftem &&
1854 rinfo->right_em == rightem &&
1855 rinfo->parent_ec == parent_ec)
1856 return rinfo;
1857 if (rinfo->left_em == rightem &&
1858 rinfo->right_em == leftem &&
1859 rinfo->parent_ec == parent_ec)
1860 return rinfo;
1861 }
1862
1863 /*
1864 * Not there, so build it, in planner context so we can re-use it. (Not
1865 * important in normal planning, but definitely so in GEQO.)
1866 */
1867 oldcontext = MemoryContextSwitchTo(root->planner_cxt);
1868
1869 /*
1870 * If either EM is a child, recursively create the corresponding
1871 * parent-to-parent clause, so that we can duplicate its rinfo_serial.
1872 */
1873 if (leftem->em_is_child || rightem->em_is_child)
1874 {
1875 EquivalenceMember *leftp = leftem->em_parent ? leftem->em_parent : leftem;
1876 EquivalenceMember *rightp = rightem->em_parent ? rightem->em_parent : rightem;
1877
1878 parent_rinfo = create_join_clause(root, ec, opno,
1879 leftp, rightp,
1880 parent_ec);
1881 }
1882
1884 opno,
1885 ec->ec_collation,
1886 leftem->em_expr,
1887 rightem->em_expr,
1888 bms_union(leftem->em_relids,
1889 rightem->em_relids),
1890 ec->ec_min_security);
1891
1892 /*
1893 * If either EM is a child, force the clause's clause_relids to include
1894 * the relid(s) of the child rel. In normal cases it would already, but
1895 * not if we are considering appendrel child relations with pseudoconstant
1896 * translated variables (i.e., UNION ALL sub-selects with constant output
1897 * items). We must do this so that join_clause_is_movable_into() will
1898 * think that the clause should be evaluated at the correct place.
1899 */
1900 if (leftem->em_is_child)
1901 rinfo->clause_relids = bms_add_members(rinfo->clause_relids,
1902 leftem->em_relids);
1903 if (rightem->em_is_child)
1904 rinfo->clause_relids = bms_add_members(rinfo->clause_relids,
1905 rightem->em_relids);
1906
1907 /* If it's a child clause, copy the parent's rinfo_serial */
1908 if (parent_rinfo)
1909 rinfo->rinfo_serial = parent_rinfo->rinfo_serial;
1910
1911 /* Mark the clause as redundant, or not */
1912 rinfo->parent_ec = parent_ec;
1913
1914 /*
1915 * We know the correct values for left_ec/right_ec, ie this particular EC,
1916 * so we can just set them directly instead of forcing another lookup.
1917 */
1918 rinfo->left_ec = ec;
1919 rinfo->right_ec = ec;
1920
1921 /* Mark it as usable with these EMs */
1922 rinfo->left_em = leftem;
1923 rinfo->right_em = rightem;
1924 /* and save it for possible re-use */
1925 ec->ec_derives = lappend(ec->ec_derives, rinfo);
1926
1927 MemoryContextSwitchTo(oldcontext);
1928
1929 return rinfo;
1930}
Bitmapset * bms_union(const Bitmapset *a, const Bitmapset *b)
Definition: bitmapset.c:251
static RestrictInfo * create_join_clause(PlannerInfo *root, EquivalenceClass *ec, Oid opno, EquivalenceMember *leftem, EquivalenceMember *rightem, EquivalenceClass *parent_ec)
Definition: equivclass.c:1817
RestrictInfo * build_implied_join_equality(PlannerInfo *root, Oid opno, Oid collation, Expr *item1, Expr *item2, Relids qualscope, Index security_level)
Definition: initsplan.c:3424
#define lfirst(lc)
Definition: pg_list.h:172
Index ec_min_security
Definition: pathnodes.h:1424
int rinfo_serial
Definition: pathnodes.h:2666

References bms_add_members(), bms_union(), build_implied_join_equality(), create_join_clause(), EquivalenceClass::ec_collation, EquivalenceClass::ec_derives, EquivalenceClass::ec_min_security, EquivalenceClass::ec_sources, EquivalenceMember::em_expr, EquivalenceMember::em_is_child, EquivalenceMember::em_relids, lappend(), lfirst, MemoryContextSwitchTo(), RestrictInfo::rinfo_serial, and root.

Referenced by create_join_clause(), generate_implied_equalities_for_column(), and generate_join_implied_equalities_normal().

◆ eclass_useful_for_merging()

bool eclass_useful_for_merging ( PlannerInfo root,
EquivalenceClass eclass,
RelOptInfo rel 
)

Definition at line 3266 of file equivclass.c.

3269{
3270 Relids relids;
3271 ListCell *lc;
3272
3273 Assert(!eclass->ec_merged);
3274
3275 /*
3276 * Won't generate joinclauses if const or single-member (the latter test
3277 * covers the volatile case too)
3278 */
3279 if (eclass->ec_has_const || list_length(eclass->ec_members) <= 1)
3280 return false;
3281
3282 /*
3283 * Note we don't test ec_broken; if we did, we'd need a separate code path
3284 * to look through ec_sources. Checking the members anyway is OK as a
3285 * possibly-overoptimistic heuristic.
3286 */
3287
3288 /* If specified rel is a child, we must consider the topmost parent rel */
3289 if (IS_OTHER_REL(rel))
3290 {
3292 relids = rel->top_parent_relids;
3293 }
3294 else
3295 relids = rel->relids;
3296
3297 /* If rel already includes all members of eclass, no point in searching */
3298 if (bms_is_subset(eclass->ec_relids, relids))
3299 return false;
3300
3301 /* To join, we need a member not in the given rel */
3302 foreach(lc, eclass->ec_members)
3303 {
3304 EquivalenceMember *cur_em = (EquivalenceMember *) lfirst(lc);
3305
3306 if (cur_em->em_is_child)
3307 continue; /* ignore children here */
3308
3309 if (!bms_overlap(cur_em->em_relids, relids))
3310 return true;
3311 }
3312
3313 return false;
3314}
#define IS_OTHER_REL(rel)
Definition: pathnodes.h:873
static struct cvec * eclass(struct vars *v, chr c, int cases)
Definition: regc_locale.c:500

References Assert, bms_is_empty, bms_is_subset(), bms_overlap(), eclass(), EquivalenceMember::em_is_child, EquivalenceMember::em_relids, IS_OTHER_REL, lfirst, list_length(), RelOptInfo::relids, and RelOptInfo::top_parent_relids.

Referenced by get_useful_ecs_for_relation(), and pathkeys_useful_for_merging().

◆ exprs_known_equal()

bool exprs_known_equal ( PlannerInfo root,
Node item1,
Node item2,
Oid  opfamily 
)

Definition at line 2498 of file equivclass.c.

2499{
2500 ListCell *lc1;
2501
2502 foreach(lc1, root->eq_classes)
2503 {
2505 bool item1member = false;
2506 bool item2member = false;
2507 ListCell *lc2;
2508
2509 /* Never match to a volatile EC */
2510 if (ec->ec_has_volatile)
2511 continue;
2512
2513 /*
2514 * It's okay to consider ec_broken ECs here. Brokenness just means we
2515 * couldn't derive all the implied clauses we'd have liked to; it does
2516 * not invalidate our knowledge that the members are equal.
2517 */
2518
2519 /* Ignore if this EC doesn't use specified opfamily */
2520 if (OidIsValid(opfamily) &&
2521 !list_member_oid(ec->ec_opfamilies, opfamily))
2522 continue;
2523
2524 foreach(lc2, ec->ec_members)
2525 {
2527
2528 if (em->em_is_child)
2529 continue; /* ignore children here */
2530 if (equal(item1, em->em_expr))
2531 item1member = true;
2532 else if (equal(item2, em->em_expr))
2533 item2member = true;
2534 /* Exit as soon as equality is proven */
2535 if (item1member && item2member)
2536 return true;
2537 }
2538 }
2539 return false;
2540}
#define OidIsValid(objectId)
Definition: c.h:732
bool equal(const void *a, const void *b)
Definition: equalfuncs.c:223
bool list_member_oid(const List *list, Oid datum)
Definition: list.c:722
List * ec_opfamilies
Definition: pathnodes.h:1413

References EquivalenceClass::ec_has_volatile, EquivalenceClass::ec_members, EquivalenceClass::ec_opfamilies, EquivalenceMember::em_expr, EquivalenceMember::em_is_child, equal(), lfirst, list_member_oid(), OidIsValid, and root.

Referenced by add_unique_group_var(), and have_partkey_equi_join().

◆ find_computable_ec_member()

EquivalenceMember * find_computable_ec_member ( PlannerInfo root,
EquivalenceClass ec,
List exprs,
Relids  relids,
bool  require_parallel_safe 
)

Definition at line 837 of file equivclass.c.

842{
843 List *exprvars;
844 ListCell *lc;
845
846 /*
847 * Pull out the Vars and quasi-Vars present in "exprs". In the typical
848 * non-appendrel case, this is just another representation of the same
849 * list. However, it does remove the distinction between the case of a
850 * list of plain expressions and a list of TargetEntrys.
851 */
852 exprvars = pull_var_clause((Node *) exprs,
856
857 foreach(lc, ec->ec_members)
858 {
860 List *emvars;
861 ListCell *lc2;
862
863 /*
864 * We shouldn't be trying to sort by an equivalence class that
865 * contains a constant, so no need to consider such cases any further.
866 */
867 if (em->em_is_const)
868 continue;
869
870 /*
871 * Ignore child members unless they belong to the requested rel.
872 */
873 if (em->em_is_child &&
874 !bms_is_subset(em->em_relids, relids))
875 continue;
876
877 /*
878 * Match if all Vars and quasi-Vars are present in "exprs".
879 */
880 emvars = pull_var_clause((Node *) em->em_expr,
884 foreach(lc2, emvars)
885 {
886 if (!list_member(exprvars, lfirst(lc2)))
887 break;
888 }
889 list_free(emvars);
890 if (lc2)
891 continue; /* we hit a non-available Var */
892
893 /*
894 * If requested, reject expressions that are not parallel-safe. We
895 * check this last because it's a rather expensive test.
896 */
897 if (require_parallel_safe &&
899 continue;
900
901 return em; /* found usable expression */
902 }
903
904 return NULL;
905}
bool is_parallel_safe(PlannerInfo *root, Node *node)
Definition: clauses.c:752
void list_free(List *list)
Definition: list.c:1546
bool list_member(const List *list, const void *datum)
Definition: list.c:661
#define PVC_INCLUDE_WINDOWFUNCS
Definition: optimizer.h:189
#define PVC_INCLUDE_PLACEHOLDERS
Definition: optimizer.h:191
#define PVC_INCLUDE_AGGREGATES
Definition: optimizer.h:187
Definition: pg_list.h:54
List * pull_var_clause(Node *node, int flags)
Definition: var.c:653

References bms_is_subset(), EquivalenceClass::ec_members, EquivalenceMember::em_expr, EquivalenceMember::em_is_child, EquivalenceMember::em_is_const, EquivalenceMember::em_relids, is_parallel_safe(), lfirst, list_free(), list_member(), pull_var_clause(), PVC_INCLUDE_AGGREGATES, PVC_INCLUDE_PLACEHOLDERS, PVC_INCLUDE_WINDOWFUNCS, and root.

Referenced by prepare_sort_from_pathkeys(), and relation_can_be_sorted_early().

◆ find_derived_clause_for_ec_member()

RestrictInfo * find_derived_clause_for_ec_member ( EquivalenceClass ec,
EquivalenceMember em 
)

Definition at line 2650 of file equivclass.c.

2652{
2653 ListCell *lc;
2654
2655 Assert(ec->ec_has_const);
2656 Assert(!em->em_is_const);
2657 foreach(lc, ec->ec_derives)
2658 {
2659 RestrictInfo *rinfo = (RestrictInfo *) lfirst(lc);
2660
2661 /*
2662 * generate_base_implied_equalities_const will have put non-const
2663 * members on the left side of derived clauses.
2664 */
2665 if (rinfo->left_em == em)
2666 return rinfo;
2667 }
2668 return NULL;
2669}

References Assert, EquivalenceClass::ec_derives, EquivalenceClass::ec_has_const, EquivalenceMember::em_is_const, and lfirst.

Referenced by get_foreign_key_join_selectivity().

◆ find_ec_member_matching_expr()

EquivalenceMember * find_ec_member_matching_expr ( EquivalenceClass ec,
Expr expr,
Relids  relids 
)

Definition at line 763 of file equivclass.c.

766{
767 ListCell *lc;
768
769 /* We ignore binary-compatible relabeling on both ends */
770 while (expr && IsA(expr, RelabelType))
771 expr = ((RelabelType *) expr)->arg;
772
773 foreach(lc, ec->ec_members)
774 {
776 Expr *emexpr;
777
778 /*
779 * We shouldn't be trying to sort by an equivalence class that
780 * contains a constant, so no need to consider such cases any further.
781 */
782 if (em->em_is_const)
783 continue;
784
785 /*
786 * Ignore child members unless they belong to the requested rel.
787 */
788 if (em->em_is_child &&
789 !bms_is_subset(em->em_relids, relids))
790 continue;
791
792 /*
793 * Match if same expression (after stripping relabel).
794 */
795 emexpr = em->em_expr;
796 while (emexpr && IsA(emexpr, RelabelType))
797 emexpr = ((RelabelType *) emexpr)->arg;
798
799 if (equal(emexpr, expr))
800 return em;
801 }
802
803 return NULL;
804}
#define IsA(nodeptr, _type_)
Definition: nodes.h:158
void * arg

References arg, bms_is_subset(), EquivalenceClass::ec_members, EquivalenceMember::em_expr, EquivalenceMember::em_is_child, EquivalenceMember::em_is_const, EquivalenceMember::em_relids, equal(), IsA, and lfirst.

Referenced by make_unique_from_pathkeys(), prepare_sort_from_pathkeys(), and relation_can_be_sorted_early().

◆ find_join_domain()

static JoinDomain * find_join_domain ( PlannerInfo root,
Relids  relids 
)
static

Definition at line 2467 of file equivclass.c.

2468{
2469 ListCell *lc;
2470
2471 foreach(lc, root->join_domains)
2472 {
2473 JoinDomain *jdomain = (JoinDomain *) lfirst(lc);
2474
2475 if (bms_is_subset(jdomain->jd_relids, relids))
2476 return jdomain;
2477 }
2478 elog(ERROR, "failed to find appropriate JoinDomain");
2479 return NULL; /* keep compiler quiet */
2480}
Relids jd_relids
Definition: pathnodes.h:1351

References bms_is_subset(), elog, ERROR, JoinDomain::jd_relids, lfirst, and root.

Referenced by reconsider_full_join_clause(), and reconsider_outer_join_clause().

◆ generate_base_implied_equalities()

void generate_base_implied_equalities ( PlannerInfo root)

Definition at line 1032 of file equivclass.c.

1033{
1034 int ec_index;
1035 ListCell *lc;
1036
1037 /*
1038 * At this point, we're done absorbing knowledge of equivalences in the
1039 * query, so no further EC merging should happen, and ECs remaining in the
1040 * eq_classes list can be considered canonical. (But note that it's still
1041 * possible for new single-member ECs to be added through
1042 * get_eclass_for_sort_expr().)
1043 */
1044 root->ec_merging_done = true;
1045
1046 ec_index = 0;
1047 foreach(lc, root->eq_classes)
1048 {
1050 bool can_generate_joinclause = false;
1051 int i;
1052
1053 Assert(ec->ec_merged == NULL); /* else shouldn't be in list */
1054 Assert(!ec->ec_broken); /* not yet anyway... */
1055
1056 /*
1057 * Generate implied equalities that are restriction clauses.
1058 * Single-member ECs won't generate any deductions, either here or at
1059 * the join level.
1060 */
1061 if (list_length(ec->ec_members) > 1)
1062 {
1063 if (ec->ec_has_const)
1065 else
1067
1068 /* Recover if we failed to generate required derived clauses */
1069 if (ec->ec_broken)
1071
1072 /* Detect whether this EC might generate join clauses */
1073 can_generate_joinclause =
1075 }
1076
1077 /*
1078 * Mark the base rels cited in each eclass (which should all exist by
1079 * now) with the eq_classes indexes of all eclasses mentioning them.
1080 * This will let us avoid searching in subsequent lookups. While
1081 * we're at it, we can mark base rels that have pending eclass joins;
1082 * this is a cheap version of has_relevant_eclass_joinclause().
1083 */
1084 i = -1;
1085 while ((i = bms_next_member(ec->ec_relids, i)) > 0)
1086 {
1087 RelOptInfo *rel = root->simple_rel_array[i];
1088
1089 /* ignore the RTE_GROUP RTE */
1090 if (i == root->group_rtindex)
1091 continue;
1092
1093 if (rel == NULL) /* must be an outer join */
1094 {
1095 Assert(bms_is_member(i, root->outer_join_rels));
1096 continue;
1097 }
1098
1100
1102 ec_index);
1103
1104 if (can_generate_joinclause)
1105 rel->has_eclass_joins = true;
1106 }
1107
1108 ec_index++;
1109 }
1110}
bool bms_is_member(int x, const Bitmapset *a)
Definition: bitmapset.c:510
static void generate_base_implied_equalities_broken(PlannerInfo *root, EquivalenceClass *ec)
Definition: equivclass.c:1322
static void generate_base_implied_equalities_no_const(PlannerInfo *root, EquivalenceClass *ec)
Definition: equivclass.c:1211
static void generate_base_implied_equalities_const(PlannerInfo *root, EquivalenceClass *ec)
Definition: equivclass.c:1116
struct EquivalenceClass * ec_merged
Definition: pathnodes.h:1426
bool has_eclass_joins
Definition: pathnodes.h:1012

References Assert, bms_add_member(), bms_is_member(), bms_membership(), BMS_MULTIPLE, bms_next_member(), EquivalenceClass::ec_broken, EquivalenceClass::ec_has_const, EquivalenceClass::ec_members, EquivalenceClass::ec_merged, EquivalenceClass::ec_relids, RelOptInfo::eclass_indexes, generate_base_implied_equalities_broken(), generate_base_implied_equalities_const(), generate_base_implied_equalities_no_const(), RelOptInfo::has_eclass_joins, i, lfirst, list_length(), RELOPT_BASEREL, RelOptInfo::reloptkind, and root.

Referenced by query_planner().

◆ generate_base_implied_equalities_broken()

static void generate_base_implied_equalities_broken ( PlannerInfo root,
EquivalenceClass ec 
)
static

Definition at line 1322 of file equivclass.c.

1324{
1325 ListCell *lc;
1326
1327 foreach(lc, ec->ec_sources)
1328 {
1329 RestrictInfo *restrictinfo = (RestrictInfo *) lfirst(lc);
1330
1331 if (ec->ec_has_const ||
1334 }
1335}
void distribute_restrictinfo_to_rels(PlannerInfo *root, RestrictInfo *restrictinfo)
Definition: initsplan.c:3195
Relids required_relids
Definition: pathnodes.h:2625

References bms_membership(), BMS_MULTIPLE, distribute_restrictinfo_to_rels(), EquivalenceClass::ec_has_const, EquivalenceClass::ec_sources, lfirst, RestrictInfo::required_relids, and root.

Referenced by generate_base_implied_equalities().

◆ generate_base_implied_equalities_const()

static void generate_base_implied_equalities_const ( PlannerInfo root,
EquivalenceClass ec 
)
static

Definition at line 1116 of file equivclass.c.

1118{
1119 EquivalenceMember *const_em = NULL;
1120 ListCell *lc;
1121
1122 /*
1123 * In the trivial case where we just had one "var = const" clause, push
1124 * the original clause back into the main planner machinery. There is
1125 * nothing to be gained by doing it differently, and we save the effort to
1126 * re-build and re-analyze an equality clause that will be exactly
1127 * equivalent to the old one.
1128 */
1129 if (list_length(ec->ec_members) == 2 &&
1130 list_length(ec->ec_sources) == 1)
1131 {
1132 RestrictInfo *restrictinfo = (RestrictInfo *) linitial(ec->ec_sources);
1133
1135 return;
1136 }
1137
1138 /*
1139 * Find the constant member to use. We prefer an actual constant to
1140 * pseudo-constants (such as Params), because the constraint exclusion
1141 * machinery might be able to exclude relations on the basis of generated
1142 * "var = const" equalities, but "var = param" won't work for that.
1143 */
1144 foreach(lc, ec->ec_members)
1145 {
1146 EquivalenceMember *cur_em = (EquivalenceMember *) lfirst(lc);
1147
1148 if (cur_em->em_is_const)
1149 {
1150 const_em = cur_em;
1151 if (IsA(cur_em->em_expr, Const))
1152 break;
1153 }
1154 }
1155 Assert(const_em != NULL);
1156
1157 /* Generate a derived equality against each other member */
1158 foreach(lc, ec->ec_members)
1159 {
1160 EquivalenceMember *cur_em = (EquivalenceMember *) lfirst(lc);
1161 Oid eq_op;
1162 RestrictInfo *rinfo;
1163
1164 Assert(!cur_em->em_is_child); /* no children yet */
1165 if (cur_em == const_em)
1166 continue;
1167 eq_op = select_equality_operator(ec,
1168 cur_em->em_datatype,
1169 const_em->em_datatype);
1170 if (!OidIsValid(eq_op))
1171 {
1172 /* failed... */
1173 ec->ec_broken = true;
1174 break;
1175 }
1176
1177 /*
1178 * We use the constant's em_jdomain as qualscope, so that if the
1179 * generated clause is variable-free (i.e, both EMs are consts) it
1180 * will be enforced at the join domain level.
1181 */
1182 rinfo = process_implied_equality(root, eq_op, ec->ec_collation,
1183 cur_em->em_expr, const_em->em_expr,
1184 const_em->em_jdomain->jd_relids,
1185 ec->ec_min_security,
1186 cur_em->em_is_const);
1187
1188 /*
1189 * If the clause didn't degenerate to a constant, fill in the correct
1190 * markings for a mergejoinable clause, and save it in ec_derives. (We
1191 * will not re-use such clauses directly, but selectivity estimation
1192 * may consult the list later. Note that this use of ec_derives does
1193 * not overlap with its use for join clauses, since we never generate
1194 * join clauses from an ec_has_const eclass.)
1195 */
1196 if (rinfo && rinfo->mergeopfamilies)
1197 {
1198 /* it's not redundant, so don't set parent_ec */
1199 rinfo->left_ec = rinfo->right_ec = ec;
1200 rinfo->left_em = cur_em;
1201 rinfo->right_em = const_em;
1202 ec->ec_derives = lappend(ec->ec_derives, rinfo);
1203 }
1204 }
1205}
static Oid select_equality_operator(EquivalenceClass *ec, Oid lefttype, Oid righttype)
Definition: equivclass.c:1781
RestrictInfo * process_implied_equality(PlannerInfo *root, Oid opno, Oid collation, Expr *item1, Expr *item2, Relids qualscope, Index security_level, bool both_const)
Definition: initsplan.c:3280

References Assert, distribute_restrictinfo_to_rels(), EquivalenceClass::ec_broken, EquivalenceClass::ec_collation, EquivalenceClass::ec_derives, EquivalenceClass::ec_members, EquivalenceClass::ec_min_security, EquivalenceClass::ec_sources, EquivalenceMember::em_datatype, EquivalenceMember::em_expr, EquivalenceMember::em_is_child, EquivalenceMember::em_is_const, EquivalenceMember::em_jdomain, IsA, JoinDomain::jd_relids, lappend(), lfirst, linitial, list_length(), OidIsValid, process_implied_equality(), root, and select_equality_operator().

Referenced by generate_base_implied_equalities().

◆ generate_base_implied_equalities_no_const()

static void generate_base_implied_equalities_no_const ( PlannerInfo root,
EquivalenceClass ec 
)
static

Definition at line 1211 of file equivclass.c.

1213{
1214 EquivalenceMember **prev_ems;
1215 ListCell *lc;
1216
1217 /*
1218 * We scan the EC members once and track the last-seen member for each
1219 * base relation. When we see another member of the same base relation,
1220 * we generate "prev_em = cur_em". This results in the minimum number of
1221 * derived clauses, but it's possible that it will fail when a different
1222 * ordering would succeed. XXX FIXME: use a UNION-FIND algorithm similar
1223 * to the way we build merged ECs. (Use a list-of-lists for each rel.)
1224 */
1225 prev_ems = (EquivalenceMember **)
1226 palloc0(root->simple_rel_array_size * sizeof(EquivalenceMember *));
1227
1228 foreach(lc, ec->ec_members)
1229 {
1230 EquivalenceMember *cur_em = (EquivalenceMember *) lfirst(lc);
1231 int relid;
1232
1233 Assert(!cur_em->em_is_child); /* no children yet */
1234 if (!bms_get_singleton_member(cur_em->em_relids, &relid))
1235 continue;
1236 Assert(relid < root->simple_rel_array_size);
1237
1238 if (prev_ems[relid] != NULL)
1239 {
1240 EquivalenceMember *prev_em = prev_ems[relid];
1241 Oid eq_op;
1242 RestrictInfo *rinfo;
1243
1244 eq_op = select_equality_operator(ec,
1245 prev_em->em_datatype,
1246 cur_em->em_datatype);
1247 if (!OidIsValid(eq_op))
1248 {
1249 /* failed... */
1250 ec->ec_broken = true;
1251 break;
1252 }
1253
1254 /*
1255 * The expressions aren't constants, so the passed qualscope will
1256 * never be used to place the generated clause. We just need to
1257 * be sure it covers both expressions, which em_relids should do.
1258 */
1259 rinfo = process_implied_equality(root, eq_op, ec->ec_collation,
1260 prev_em->em_expr, cur_em->em_expr,
1261 cur_em->em_relids,
1262 ec->ec_min_security,
1263 false);
1264
1265 /*
1266 * If the clause didn't degenerate to a constant, fill in the
1267 * correct markings for a mergejoinable clause. We don't put it
1268 * in ec_derives however; we don't currently need to re-find such
1269 * clauses, and we don't want to clutter that list with non-join
1270 * clauses.
1271 */
1272 if (rinfo && rinfo->mergeopfamilies)
1273 {
1274 /* it's not redundant, so don't set parent_ec */
1275 rinfo->left_ec = rinfo->right_ec = ec;
1276 rinfo->left_em = prev_em;
1277 rinfo->right_em = cur_em;
1278 }
1279 }
1280 prev_ems[relid] = cur_em;
1281 }
1282
1283 pfree(prev_ems);
1284
1285 /*
1286 * We also have to make sure that all the Vars used in the member clauses
1287 * will be available at any join node we might try to reference them at.
1288 * For the moment we force all the Vars to be available at all join nodes
1289 * for this eclass. Perhaps this could be improved by doing some
1290 * pre-analysis of which members we prefer to join, but it's no worse than
1291 * what happened in the pre-8.3 code. (Note: rebuild_eclass_attr_needed
1292 * needs to match this code.)
1293 */
1294 foreach(lc, ec->ec_members)
1295 {
1296 EquivalenceMember *cur_em = (EquivalenceMember *) lfirst(lc);
1297 List *vars = pull_var_clause((Node *) cur_em->em_expr,
1301
1303 list_free(vars);
1304 }
1305}
bool bms_get_singleton_member(const Bitmapset *a, int *member)
Definition: bitmapset.c:715
void add_vars_to_targetlist(PlannerInfo *root, List *vars, Relids where_needed)
Definition: initsplan.c:282
void pfree(void *pointer)
Definition: mcxt.c:1521
void * palloc0(Size size)
Definition: mcxt.c:1347
#define PVC_RECURSE_AGGREGATES
Definition: optimizer.h:188
#define PVC_RECURSE_WINDOWFUNCS
Definition: optimizer.h:190
Definition: regcomp.c:282

References add_vars_to_targetlist(), Assert, bms_get_singleton_member(), EquivalenceClass::ec_broken, EquivalenceClass::ec_collation, EquivalenceClass::ec_members, EquivalenceClass::ec_min_security, EquivalenceClass::ec_relids, EquivalenceMember::em_datatype, EquivalenceMember::em_expr, EquivalenceMember::em_is_child, EquivalenceMember::em_relids, lfirst, list_free(), OidIsValid, palloc0(), pfree(), process_implied_equality(), pull_var_clause(), PVC_INCLUDE_PLACEHOLDERS, PVC_RECURSE_AGGREGATES, PVC_RECURSE_WINDOWFUNCS, root, and select_equality_operator().

Referenced by generate_base_implied_equalities().

◆ generate_implied_equalities_for_column()

List * generate_implied_equalities_for_column ( PlannerInfo root,
RelOptInfo rel,
ec_matches_callback_type  callback,
void *  callback_arg,
Relids  prohibited_rels 
)

Definition at line 3014 of file equivclass.c.

3019{
3020 List *result = NIL;
3021 bool is_child_rel = (rel->reloptkind == RELOPT_OTHER_MEMBER_REL);
3022 Relids parent_relids;
3023 int i;
3024
3025 /* Should be OK to rely on eclass_indexes */
3026 Assert(root->ec_merging_done);
3027
3028 /* Indexes are available only on base or "other" member relations. */
3029 Assert(IS_SIMPLE_REL(rel));
3030
3031 /* If it's a child rel, we'll need to know what its parent(s) are */
3032 if (is_child_rel)
3033 parent_relids = find_childrel_parents(root, rel);
3034 else
3035 parent_relids = NULL; /* not used, but keep compiler quiet */
3036
3037 i = -1;
3038 while ((i = bms_next_member(rel->eclass_indexes, i)) >= 0)
3039 {
3040 EquivalenceClass *cur_ec = (EquivalenceClass *) list_nth(root->eq_classes, i);
3041 EquivalenceMember *cur_em;
3042 ListCell *lc2;
3043
3044 /* Sanity check eclass_indexes only contain ECs for rel */
3045 Assert(is_child_rel || bms_is_subset(rel->relids, cur_ec->ec_relids));
3046
3047 /*
3048 * Won't generate joinclauses if const or single-member (the latter
3049 * test covers the volatile case too)
3050 */
3051 if (cur_ec->ec_has_const || list_length(cur_ec->ec_members) <= 1)
3052 continue;
3053
3054 /*
3055 * Scan members, looking for a match to the target column. Note that
3056 * child EC members are considered, but only when they belong to the
3057 * target relation. (Unlike regular members, the same expression
3058 * could be a child member of more than one EC. Therefore, it's
3059 * potentially order-dependent which EC a child relation's target
3060 * column gets matched to. This is annoying but it only happens in
3061 * corner cases, so for now we live with just reporting the first
3062 * match. See also get_eclass_for_sort_expr.)
3063 */
3064 cur_em = NULL;
3065 foreach(lc2, cur_ec->ec_members)
3066 {
3067 cur_em = (EquivalenceMember *) lfirst(lc2);
3068 if (bms_equal(cur_em->em_relids, rel->relids) &&
3069 callback(root, rel, cur_ec, cur_em, callback_arg))
3070 break;
3071 cur_em = NULL;
3072 }
3073
3074 if (!cur_em)
3075 continue;
3076
3077 /*
3078 * Found our match. Scan the other EC members and attempt to generate
3079 * joinclauses.
3080 */
3081 foreach(lc2, cur_ec->ec_members)
3082 {
3083 EquivalenceMember *other_em = (EquivalenceMember *) lfirst(lc2);
3084 Oid eq_op;
3085 RestrictInfo *rinfo;
3086
3087 if (other_em->em_is_child)
3088 continue; /* ignore children here */
3089
3090 /* Make sure it'll be a join to a different rel */
3091 if (other_em == cur_em ||
3092 bms_overlap(other_em->em_relids, rel->relids))
3093 continue;
3094
3095 /* Forget it if caller doesn't want joins to this rel */
3096 if (bms_overlap(other_em->em_relids, prohibited_rels))
3097 continue;
3098
3099 /*
3100 * Also, if this is a child rel, avoid generating a useless join
3101 * to its parent rel(s).
3102 */
3103 if (is_child_rel &&
3104 bms_overlap(parent_relids, other_em->em_relids))
3105 continue;
3106
3107 eq_op = select_equality_operator(cur_ec,
3108 cur_em->em_datatype,
3109 other_em->em_datatype);
3110 if (!OidIsValid(eq_op))
3111 continue;
3112
3113 /* set parent_ec to mark as redundant with other joinclauses */
3114 rinfo = create_join_clause(root, cur_ec, eq_op,
3115 cur_em, other_em,
3116 cur_ec);
3117
3118 result = lappend(result, rinfo);
3119 }
3120
3121 /*
3122 * If somehow we failed to create any join clauses, we might as well
3123 * keep scanning the ECs for another match. But if we did make any,
3124 * we're done, because we don't want to return non-redundant clauses.
3125 */
3126 if (result)
3127 break;
3128 }
3129
3130 return result;
3131}
bool bms_equal(const Bitmapset *a, const Bitmapset *b)
Definition: bitmapset.c:142
@ RELOPT_OTHER_MEMBER_REL
Definition: pathnodes.h:848
#define NIL
Definition: pg_list.h:68
Relids find_childrel_parents(PlannerInfo *root, RelOptInfo *rel)
Definition: relnode.c:1509
static void callback(struct sockaddr *addr, struct sockaddr *mask, void *unused)
Definition: test_ifaddrs.c:46

References Assert, bms_equal(), bms_is_subset(), bms_next_member(), bms_overlap(), callback(), create_join_clause(), EquivalenceClass::ec_has_const, EquivalenceClass::ec_members, EquivalenceClass::ec_relids, RelOptInfo::eclass_indexes, EquivalenceMember::em_datatype, EquivalenceMember::em_is_child, EquivalenceMember::em_relids, find_childrel_parents(), i, IS_SIMPLE_REL, lappend(), lfirst, list_length(), list_nth(), NIL, OidIsValid, RelOptInfo::relids, RELOPT_OTHER_MEMBER_REL, RelOptInfo::reloptkind, root, and select_equality_operator().

Referenced by create_tidscan_paths(), match_eclass_clauses_to_index(), and postgresGetForeignPaths().

◆ generate_join_implied_equalities()

List * generate_join_implied_equalities ( PlannerInfo root,
Relids  join_relids,
Relids  outer_relids,
RelOptInfo inner_rel,
SpecialJoinInfo sjinfo 
)

Definition at line 1385 of file equivclass.c.

1390{
1391 List *result = NIL;
1392 Relids inner_relids = inner_rel->relids;
1393 Relids nominal_inner_relids;
1394 Relids nominal_join_relids;
1395 Bitmapset *matching_ecs;
1396 int i;
1397
1398 /* If inner rel is a child, extra setup work is needed */
1399 if (IS_OTHER_REL(inner_rel))
1400 {
1402
1403 /* Fetch relid set for the topmost parent rel */
1404 nominal_inner_relids = inner_rel->top_parent_relids;
1405 /* ECs will be marked with the parent's relid, not the child's */
1406 nominal_join_relids = bms_union(outer_relids, nominal_inner_relids);
1407 nominal_join_relids = add_outer_joins_to_relids(root,
1408 nominal_join_relids,
1409 sjinfo,
1410 NULL);
1411 }
1412 else
1413 {
1414 nominal_inner_relids = inner_relids;
1415 nominal_join_relids = join_relids;
1416 }
1417
1418 /*
1419 * Examine all potentially-relevant eclasses.
1420 *
1421 * If we are considering an outer join, we must include "join" clauses
1422 * that mention either input rel plus the outer join's relid; these
1423 * represent post-join filter clauses that have to be applied at this
1424 * join. We don't have infrastructure that would let us identify such
1425 * eclasses cheaply, so just fall back to considering all eclasses
1426 * mentioning anything in nominal_join_relids.
1427 *
1428 * At inner joins, we can be smarter: only consider eclasses mentioning
1429 * both input rels.
1430 */
1431 if (sjinfo && sjinfo->ojrelid != 0)
1432 matching_ecs = get_eclass_indexes_for_relids(root, nominal_join_relids);
1433 else
1434 matching_ecs = get_common_eclass_indexes(root, nominal_inner_relids,
1435 outer_relids);
1436
1437 i = -1;
1438 while ((i = bms_next_member(matching_ecs, i)) >= 0)
1439 {
1440 EquivalenceClass *ec = (EquivalenceClass *) list_nth(root->eq_classes, i);
1441 List *sublist = NIL;
1442
1443 /* ECs containing consts do not need any further enforcement */
1444 if (ec->ec_has_const)
1445 continue;
1446
1447 /* Single-member ECs won't generate any deductions */
1448 if (list_length(ec->ec_members) <= 1)
1449 continue;
1450
1451 /* Sanity check that this eclass overlaps the join */
1452 Assert(bms_overlap(ec->ec_relids, nominal_join_relids));
1453
1454 if (!ec->ec_broken)
1456 ec,
1457 join_relids,
1458 outer_relids,
1459 inner_relids);
1460
1461 /* Recover if we failed to generate required derived clauses */
1462 if (ec->ec_broken)
1464 ec,
1465 nominal_join_relids,
1466 outer_relids,
1467 nominal_inner_relids,
1468 inner_rel);
1469
1470 result = list_concat(result, sublist);
1471 }
1472
1473 return result;
1474}
static List * generate_join_implied_equalities_normal(PlannerInfo *root, EquivalenceClass *ec, Relids join_relids, Relids outer_relids, Relids inner_relids)
Definition: equivclass.c:1556
static Bitmapset * get_common_eclass_indexes(PlannerInfo *root, Relids relids1, Relids relids2)
Definition: equivclass.c:3421
static List * generate_join_implied_equalities_broken(PlannerInfo *root, EquivalenceClass *ec, Relids nominal_join_relids, Relids outer_relids, Relids nominal_inner_relids, RelOptInfo *inner_rel)
Definition: equivclass.c:1732
Relids add_outer_joins_to_relids(PlannerInfo *root, Relids input_relids, SpecialJoinInfo *sjinfo, List **pushed_down_joins)
Definition: joinrels.c:801
List * list_concat(List *list1, const List *list2)
Definition: list.c:561

References add_outer_joins_to_relids(), Assert, bms_is_empty, bms_next_member(), bms_overlap(), bms_union(), EquivalenceClass::ec_broken, EquivalenceClass::ec_has_const, EquivalenceClass::ec_members, EquivalenceClass::ec_relids, generate_join_implied_equalities_broken(), generate_join_implied_equalities_normal(), get_common_eclass_indexes(), get_eclass_indexes_for_relids(), i, IS_OTHER_REL, list_concat(), list_length(), list_nth(), NIL, SpecialJoinInfo::ojrelid, RelOptInfo::relids, root, and RelOptInfo::top_parent_relids.

Referenced by build_joinrel_restrictlist(), check_index_predicates(), get_baserel_parampathinfo(), get_joinrel_parampathinfo(), and reduce_unique_semijoins().

◆ generate_join_implied_equalities_broken()

static List * generate_join_implied_equalities_broken ( PlannerInfo root,
EquivalenceClass ec,
Relids  nominal_join_relids,
Relids  outer_relids,
Relids  nominal_inner_relids,
RelOptInfo inner_rel 
)
static

Definition at line 1732 of file equivclass.c.

1738{
1739 List *result = NIL;
1740 ListCell *lc;
1741
1742 foreach(lc, ec->ec_sources)
1743 {
1744 RestrictInfo *restrictinfo = (RestrictInfo *) lfirst(lc);
1745 Relids clause_relids = restrictinfo->required_relids;
1746
1747 if (bms_is_subset(clause_relids, nominal_join_relids) &&
1748 !bms_is_subset(clause_relids, outer_relids) &&
1749 !bms_is_subset(clause_relids, nominal_inner_relids))
1750 result = lappend(result, restrictinfo);
1751 }
1752
1753 /*
1754 * If we have to translate, just brute-force apply adjust_appendrel_attrs
1755 * to all the RestrictInfos at once. This will result in returning
1756 * RestrictInfos that are not listed in ec_derives, but there shouldn't be
1757 * any duplication, and it's a sufficiently narrow corner case that we
1758 * shouldn't sweat too much over it anyway.
1759 *
1760 * Since inner_rel might be an indirect descendant of the baserel
1761 * mentioned in the ec_sources clauses, we have to be prepared to apply
1762 * multiple levels of Var translation.
1763 */
1764 if (IS_OTHER_REL(inner_rel) && result != NIL)
1766 (Node *) result,
1767 inner_rel,
1768 inner_rel->top_parent);
1769
1770 return result;
1771}

References adjust_appendrel_attrs_multilevel(), bms_is_subset(), EquivalenceClass::ec_sources, IS_OTHER_REL, lappend(), lfirst, NIL, RestrictInfo::required_relids, and root.

Referenced by generate_join_implied_equalities(), and generate_join_implied_equalities_for_ecs().

◆ generate_join_implied_equalities_for_ecs()

List * generate_join_implied_equalities_for_ecs ( PlannerInfo root,
List eclasses,
Relids  join_relids,
Relids  outer_relids,
RelOptInfo inner_rel 
)

Definition at line 1485 of file equivclass.c.

1490{
1491 List *result = NIL;
1492 Relids inner_relids = inner_rel->relids;
1493 Relids nominal_inner_relids;
1494 Relids nominal_join_relids;
1495 ListCell *lc;
1496
1497 /* If inner rel is a child, extra setup work is needed */
1498 if (IS_OTHER_REL(inner_rel))
1499 {
1501
1502 /* Fetch relid set for the topmost parent rel */
1503 nominal_inner_relids = inner_rel->top_parent_relids;
1504 /* ECs will be marked with the parent's relid, not the child's */
1505 nominal_join_relids = bms_union(outer_relids, nominal_inner_relids);
1506 }
1507 else
1508 {
1509 nominal_inner_relids = inner_relids;
1510 nominal_join_relids = join_relids;
1511 }
1512
1513 foreach(lc, eclasses)
1514 {
1516 List *sublist = NIL;
1517
1518 /* ECs containing consts do not need any further enforcement */
1519 if (ec->ec_has_const)
1520 continue;
1521
1522 /* Single-member ECs won't generate any deductions */
1523 if (list_length(ec->ec_members) <= 1)
1524 continue;
1525
1526 /* We can quickly ignore any that don't overlap the join, too */
1527 if (!bms_overlap(ec->ec_relids, nominal_join_relids))
1528 continue;
1529
1530 if (!ec->ec_broken)
1532 ec,
1533 join_relids,
1534 outer_relids,
1535 inner_relids);
1536
1537 /* Recover if we failed to generate required derived clauses */
1538 if (ec->ec_broken)
1540 ec,
1541 nominal_join_relids,
1542 outer_relids,
1543 nominal_inner_relids,
1544 inner_rel);
1545
1546 result = list_concat(result, sublist);
1547 }
1548
1549 return result;
1550}

References Assert, bms_is_empty, bms_overlap(), bms_union(), EquivalenceClass::ec_broken, EquivalenceClass::ec_has_const, EquivalenceClass::ec_members, EquivalenceClass::ec_relids, generate_join_implied_equalities_broken(), generate_join_implied_equalities_normal(), IS_OTHER_REL, lfirst, list_concat(), list_length(), NIL, RelOptInfo::relids, root, and RelOptInfo::top_parent_relids.

Referenced by get_joinrel_parampathinfo().

◆ generate_join_implied_equalities_normal()

static List * generate_join_implied_equalities_normal ( PlannerInfo root,
EquivalenceClass ec,
Relids  join_relids,
Relids  outer_relids,
Relids  inner_relids 
)
static

Definition at line 1556 of file equivclass.c.

1561{
1562 List *result = NIL;
1563 List *new_members = NIL;
1564 List *outer_members = NIL;
1565 List *inner_members = NIL;
1566 ListCell *lc1;
1567
1568 /*
1569 * First, scan the EC to identify member values that are computable at the
1570 * outer rel, at the inner rel, or at this relation but not in either
1571 * input rel. The outer-rel members should already be enforced equal,
1572 * likewise for the inner-rel members. We'll need to create clauses to
1573 * enforce that any newly computable members are all equal to each other
1574 * as well as to at least one input member, plus enforce at least one
1575 * outer-rel member equal to at least one inner-rel member.
1576 */
1577 foreach(lc1, ec->ec_members)
1578 {
1579 EquivalenceMember *cur_em = (EquivalenceMember *) lfirst(lc1);
1580
1581 /*
1582 * We don't need to check explicitly for child EC members. This test
1583 * against join_relids will cause them to be ignored except when
1584 * considering a child inner rel, which is what we want.
1585 */
1586 if (!bms_is_subset(cur_em->em_relids, join_relids))
1587 continue; /* not computable yet, or wrong child */
1588
1589 if (bms_is_subset(cur_em->em_relids, outer_relids))
1590 outer_members = lappend(outer_members, cur_em);
1591 else if (bms_is_subset(cur_em->em_relids, inner_relids))
1592 inner_members = lappend(inner_members, cur_em);
1593 else
1594 new_members = lappend(new_members, cur_em);
1595 }
1596
1597 /*
1598 * First, select the joinclause if needed. We can equate any one outer
1599 * member to any one inner member, but we have to find a datatype
1600 * combination for which an opfamily member operator exists. If we have
1601 * choices, we prefer simple Var members (possibly with RelabelType) since
1602 * these are (a) cheapest to compute at runtime and (b) most likely to
1603 * have useful statistics. Also, prefer operators that are also
1604 * hashjoinable.
1605 */
1606 if (outer_members && inner_members)
1607 {
1608 EquivalenceMember *best_outer_em = NULL;
1609 EquivalenceMember *best_inner_em = NULL;
1610 Oid best_eq_op = InvalidOid;
1611 int best_score = -1;
1612 RestrictInfo *rinfo;
1613
1614 foreach(lc1, outer_members)
1615 {
1616 EquivalenceMember *outer_em = (EquivalenceMember *) lfirst(lc1);
1617 ListCell *lc2;
1618
1619 foreach(lc2, inner_members)
1620 {
1621 EquivalenceMember *inner_em = (EquivalenceMember *) lfirst(lc2);
1622 Oid eq_op;
1623 int score;
1624
1625 eq_op = select_equality_operator(ec,
1626 outer_em->em_datatype,
1627 inner_em->em_datatype);
1628 if (!OidIsValid(eq_op))
1629 continue;
1630 score = 0;
1631 if (IsA(outer_em->em_expr, Var) ||
1632 (IsA(outer_em->em_expr, RelabelType) &&
1633 IsA(((RelabelType *) outer_em->em_expr)->arg, Var)))
1634 score++;
1635 if (IsA(inner_em->em_expr, Var) ||
1636 (IsA(inner_em->em_expr, RelabelType) &&
1637 IsA(((RelabelType *) inner_em->em_expr)->arg, Var)))
1638 score++;
1639 if (op_hashjoinable(eq_op,
1640 exprType((Node *) outer_em->em_expr)))
1641 score++;
1642 if (score > best_score)
1643 {
1644 best_outer_em = outer_em;
1645 best_inner_em = inner_em;
1646 best_eq_op = eq_op;
1647 best_score = score;
1648 if (best_score == 3)
1649 break; /* no need to look further */
1650 }
1651 }
1652 if (best_score == 3)
1653 break; /* no need to look further */
1654 }
1655 if (best_score < 0)
1656 {
1657 /* failed... */
1658 ec->ec_broken = true;
1659 return NIL;
1660 }
1661
1662 /*
1663 * Create clause, setting parent_ec to mark it as redundant with other
1664 * joinclauses
1665 */
1666 rinfo = create_join_clause(root, ec, best_eq_op,
1667 best_outer_em, best_inner_em,
1668 ec);
1669
1670 result = lappend(result, rinfo);
1671 }
1672
1673 /*
1674 * Now deal with building restrictions for any expressions that involve
1675 * Vars from both sides of the join. We have to equate all of these to
1676 * each other as well as to at least one old member (if any).
1677 *
1678 * XXX as in generate_base_implied_equalities_no_const, we could be a lot
1679 * smarter here to avoid unnecessary failures in cross-type situations.
1680 * For now, use the same left-to-right method used there.
1681 */
1682 if (new_members)
1683 {
1684 List *old_members = list_concat(outer_members, inner_members);
1685 EquivalenceMember *prev_em = NULL;
1686 RestrictInfo *rinfo;
1687
1688 /* For now, arbitrarily take the first old_member as the one to use */
1689 if (old_members)
1690 new_members = lappend(new_members, linitial(old_members));
1691
1692 foreach(lc1, new_members)
1693 {
1694 EquivalenceMember *cur_em = (EquivalenceMember *) lfirst(lc1);
1695
1696 if (prev_em != NULL)
1697 {
1698 Oid eq_op;
1699
1700 eq_op = select_equality_operator(ec,
1701 prev_em->em_datatype,
1702 cur_em->em_datatype);
1703 if (!OidIsValid(eq_op))
1704 {
1705 /* failed... */
1706 ec->ec_broken = true;
1707 return NIL;
1708 }
1709 /* do NOT set parent_ec, this qual is not redundant! */
1710 rinfo = create_join_clause(root, ec, eq_op,
1711 prev_em, cur_em,
1712 NULL);
1713
1714 result = lappend(result, rinfo);
1715 }
1716 prev_em = cur_em;
1717 }
1718 }
1719
1720 return result;
1721}
bool op_hashjoinable(Oid opno, Oid inputtype)
Definition: lsyscache.c:1464
#define InvalidOid
Definition: postgres_ext.h:37
Definition: primnodes.h:262

References bms_is_subset(), create_join_clause(), EquivalenceClass::ec_broken, EquivalenceClass::ec_members, EquivalenceMember::em_datatype, EquivalenceMember::em_expr, EquivalenceMember::em_relids, exprType(), InvalidOid, IsA, lappend(), lfirst, linitial, list_concat(), NIL, OidIsValid, op_hashjoinable(), root, and select_equality_operator().

Referenced by generate_join_implied_equalities(), and generate_join_implied_equalities_for_ecs().

◆ get_common_eclass_indexes()

static Bitmapset * get_common_eclass_indexes ( PlannerInfo root,
Relids  relids1,
Relids  relids2 
)
static

Definition at line 3421 of file equivclass.c.

3422{
3423 Bitmapset *rel1ecs;
3424 Bitmapset *rel2ecs;
3425 int relid;
3426
3427 rel1ecs = get_eclass_indexes_for_relids(root, relids1);
3428
3429 /*
3430 * We can get away with just using the relation's eclass_indexes directly
3431 * when relids2 is a singleton set.
3432 */
3433 if (bms_get_singleton_member(relids2, &relid))
3434 rel2ecs = root->simple_rel_array[relid]->eclass_indexes;
3435 else
3436 rel2ecs = get_eclass_indexes_for_relids(root, relids2);
3437
3438 /* Calculate and return the common EC indexes, recycling the left input. */
3439 return bms_int_members(rel1ecs, rel2ecs);
3440}
Bitmapset * bms_int_members(Bitmapset *a, const Bitmapset *b)
Definition: bitmapset.c:1109

References bms_get_singleton_member(), bms_int_members(), get_eclass_indexes_for_relids(), and root.

Referenced by generate_join_implied_equalities(), and have_relevant_eclass_joinclause().

◆ get_eclass_for_sort_expr()

EquivalenceClass * get_eclass_for_sort_expr ( PlannerInfo root,
Expr expr,
List opfamilies,
Oid  opcintype,
Oid  collation,
Index  sortref,
Relids  rel,
bool  create_it 
)

Definition at line 586 of file equivclass.c.

594{
595 JoinDomain *jdomain;
596 Relids expr_relids;
597 EquivalenceClass *newec;
598 EquivalenceMember *newem;
599 ListCell *lc1;
600 MemoryContext oldcontext;
601
602 /*
603 * Ensure the expression exposes the correct type and collation.
604 */
605 expr = canonicalize_ec_expression(expr, opcintype, collation);
606
607 /*
608 * Since SortGroupClause nodes are top-level expressions (GROUP BY, ORDER
609 * BY, etc), they can be presumed to belong to the top JoinDomain.
610 */
611 jdomain = linitial_node(JoinDomain, root->join_domains);
612
613 /*
614 * Scan through the existing EquivalenceClasses for a match
615 */
616 foreach(lc1, root->eq_classes)
617 {
618 EquivalenceClass *cur_ec = (EquivalenceClass *) lfirst(lc1);
619 ListCell *lc2;
620
621 /*
622 * Never match to a volatile EC, except when we are looking at another
623 * reference to the same volatile SortGroupClause.
624 */
625 if (cur_ec->ec_has_volatile &&
626 (sortref == 0 || sortref != cur_ec->ec_sortref))
627 continue;
628
629 if (collation != cur_ec->ec_collation)
630 continue;
631 if (!equal(opfamilies, cur_ec->ec_opfamilies))
632 continue;
633
634 foreach(lc2, cur_ec->ec_members)
635 {
636 EquivalenceMember *cur_em = (EquivalenceMember *) lfirst(lc2);
637
638 /*
639 * Ignore child members unless they match the request.
640 */
641 if (cur_em->em_is_child &&
642 !bms_equal(cur_em->em_relids, rel))
643 continue;
644
645 /*
646 * Match constants only within the same JoinDomain (see
647 * optimizer/README).
648 */
649 if (cur_em->em_is_const && cur_em->em_jdomain != jdomain)
650 continue;
651
652 if (opcintype == cur_em->em_datatype &&
653 equal(expr, cur_em->em_expr))
654 return cur_ec; /* Match! */
655 }
656 }
657
658 /* No match; does caller want a NULL result? */
659 if (!create_it)
660 return NULL;
661
662 /*
663 * OK, build a new single-member EC
664 *
665 * Here, we must be sure that we construct the EC in the right context.
666 */
667 oldcontext = MemoryContextSwitchTo(root->planner_cxt);
668
669 newec = makeNode(EquivalenceClass);
670 newec->ec_opfamilies = list_copy(opfamilies);
671 newec->ec_collation = collation;
672 newec->ec_members = NIL;
673 newec->ec_sources = NIL;
674 newec->ec_derives = NIL;
675 newec->ec_relids = NULL;
676 newec->ec_has_const = false;
678 newec->ec_broken = false;
679 newec->ec_sortref = sortref;
680 newec->ec_min_security = UINT_MAX;
681 newec->ec_max_security = 0;
682 newec->ec_merged = NULL;
683
684 if (newec->ec_has_volatile && sortref == 0) /* should not happen */
685 elog(ERROR, "volatile EquivalenceClass has no sortref");
686
687 /*
688 * Get the precise set of relids appearing in the expression.
689 */
690 expr_relids = pull_varnos(root, (Node *) expr);
691
692 newem = add_eq_member(newec, copyObject(expr), expr_relids,
693 jdomain, NULL, opcintype);
694
695 /*
696 * add_eq_member doesn't check for volatile functions, set-returning
697 * functions, aggregates, or window functions, but such could appear in
698 * sort expressions; so we have to check whether its const-marking was
699 * correct.
700 */
701 if (newec->ec_has_const)
702 {
703 if (newec->ec_has_volatile ||
704 expression_returns_set((Node *) expr) ||
705 contain_agg_clause((Node *) expr) ||
707 {
708 newec->ec_has_const = false;
709 newem->em_is_const = false;
710 }
711 }
712
713 root->eq_classes = lappend(root->eq_classes, newec);
714
715 /*
716 * If EC merging is already complete, we have to mop up by adding the new
717 * EC to the eclass_indexes of the relation(s) mentioned in it.
718 */
719 if (root->ec_merging_done)
720 {
721 int ec_index = list_length(root->eq_classes) - 1;
722 int i = -1;
723
724 while ((i = bms_next_member(newec->ec_relids, i)) > 0)
725 {
726 RelOptInfo *rel = root->simple_rel_array[i];
727
728 /* ignore the RTE_GROUP RTE */
729 if (i == root->group_rtindex)
730 continue;
731
732 if (rel == NULL) /* must be an outer join */
733 {
734 Assert(bms_is_member(i, root->outer_join_rels));
735 continue;
736 }
737
739
741 ec_index);
742 }
743 }
744
745 MemoryContextSwitchTo(oldcontext);
746
747 return newec;
748}
bool contain_agg_clause(Node *clause)
Definition: clauses.c:177
bool contain_window_function(Node *clause)
Definition: clauses.c:214
bool contain_volatile_functions(Node *clause)
Definition: clauses.c:537
Expr * canonicalize_ec_expression(Expr *expr, Oid req_type, Oid req_collation)
Definition: equivclass.c:471
List * list_copy(const List *oldlist)
Definition: list.c:1573
bool expression_returns_set(Node *clause)
Definition: nodeFuncs.c:763
#define copyObject(obj)
Definition: nodes.h:224
#define linitial_node(type, l)
Definition: pg_list.h:181
Index ec_max_security
Definition: pathnodes.h:1425
Relids pull_varnos(PlannerInfo *root, Node *node)
Definition: var.c:114

References add_eq_member(), Assert, bms_add_member(), bms_equal(), bms_is_member(), bms_next_member(), canonicalize_ec_expression(), contain_agg_clause(), contain_volatile_functions(), contain_window_function(), copyObject, EquivalenceClass::ec_broken, EquivalenceClass::ec_collation, EquivalenceClass::ec_derives, EquivalenceClass::ec_has_const, EquivalenceClass::ec_has_volatile, EquivalenceClass::ec_max_security, EquivalenceClass::ec_members, EquivalenceClass::ec_merged, EquivalenceClass::ec_min_security, EquivalenceClass::ec_opfamilies, EquivalenceClass::ec_relids, EquivalenceClass::ec_sortref, EquivalenceClass::ec_sources, RelOptInfo::eclass_indexes, elog, EquivalenceMember::em_datatype, EquivalenceMember::em_expr, EquivalenceMember::em_is_child, EquivalenceMember::em_is_const, EquivalenceMember::em_jdomain, EquivalenceMember::em_relids, equal(), ERROR, expression_returns_set(), i, lappend(), lfirst, linitial_node, list_copy(), list_length(), makeNode, MemoryContextSwitchTo(), NIL, pull_varnos(), RELOPT_BASEREL, RelOptInfo::reloptkind, and root.

Referenced by convert_subquery_pathkeys(), initialize_mergeclause_eclasses(), and make_pathkey_from_sortinfo().

◆ get_eclass_indexes_for_relids()

static Bitmapset * get_eclass_indexes_for_relids ( PlannerInfo root,
Relids  relids 
)
static

Definition at line 3387 of file equivclass.c.

3388{
3389 Bitmapset *ec_indexes = NULL;
3390 int i = -1;
3391
3392 /* Should be OK to rely on eclass_indexes */
3393 Assert(root->ec_merging_done);
3394
3395 while ((i = bms_next_member(relids, i)) > 0)
3396 {
3397 RelOptInfo *rel = root->simple_rel_array[i];
3398
3399 /* ignore the RTE_GROUP RTE */
3400 if (i == root->group_rtindex)
3401 continue;
3402
3403 if (rel == NULL) /* must be an outer join */
3404 {
3405 Assert(bms_is_member(i, root->outer_join_rels));
3406 continue;
3407 }
3408
3409 ec_indexes = bms_add_members(ec_indexes, rel->eclass_indexes);
3410 }
3411 return ec_indexes;
3412}

References Assert, bms_add_members(), bms_is_member(), bms_next_member(), RelOptInfo::eclass_indexes, i, and root.

Referenced by add_child_join_rel_equivalences(), generate_join_implied_equalities(), get_common_eclass_indexes(), and has_relevant_eclass_joinclause().

◆ has_relevant_eclass_joinclause()

bool has_relevant_eclass_joinclause ( PlannerInfo root,
RelOptInfo rel1 
)

Definition at line 3222 of file equivclass.c.

3223{
3224 Bitmapset *matched_ecs;
3225 int i;
3226
3227 /* Examine only eclasses mentioning rel1 */
3228 matched_ecs = get_eclass_indexes_for_relids(root, rel1->relids);
3229
3230 i = -1;
3231 while ((i = bms_next_member(matched_ecs, i)) >= 0)
3232 {
3233 EquivalenceClass *ec = (EquivalenceClass *) list_nth(root->eq_classes,
3234 i);
3235
3236 /*
3237 * Won't generate joinclauses if single-member (this test covers the
3238 * volatile case too)
3239 */
3240 if (list_length(ec->ec_members) <= 1)
3241 continue;
3242
3243 /*
3244 * Per the comment in have_relevant_eclass_joinclause, it's sufficient
3245 * to find an EC that mentions both this rel and some other rel.
3246 */
3247 if (!bms_is_subset(ec->ec_relids, rel1->relids))
3248 return true;
3249 }
3250
3251 return false;
3252}

References bms_is_subset(), bms_next_member(), EquivalenceClass::ec_members, EquivalenceClass::ec_relids, get_eclass_indexes_for_relids(), i, list_length(), list_nth(), RelOptInfo::relids, and root.

Referenced by build_join_rel().

◆ have_relevant_eclass_joinclause()

bool have_relevant_eclass_joinclause ( PlannerInfo root,
RelOptInfo rel1,
RelOptInfo rel2 
)

Definition at line 3146 of file equivclass.c.

3148{
3149 Bitmapset *matching_ecs;
3150 int i;
3151
3152 /*
3153 * Examine only eclasses mentioning both rel1 and rel2.
3154 *
3155 * Note that we do not consider the possibility of an eclass generating
3156 * "join" clauses that mention just one of the rels plus an outer join
3157 * that could be formed from them. Although such clauses must be
3158 * correctly enforced when we form the outer join, they don't seem like
3159 * sufficient reason to prioritize this join over other ones. The join
3160 * ordering rules will force the join to be made when necessary.
3161 */
3162 matching_ecs = get_common_eclass_indexes(root, rel1->relids,
3163 rel2->relids);
3164
3165 i = -1;
3166 while ((i = bms_next_member(matching_ecs, i)) >= 0)
3167 {
3168 EquivalenceClass *ec = (EquivalenceClass *) list_nth(root->eq_classes,
3169 i);
3170
3171 /*
3172 * Sanity check that get_common_eclass_indexes gave only ECs
3173 * containing both rels.
3174 */
3175 Assert(bms_overlap(rel1->relids, ec->ec_relids));
3176 Assert(bms_overlap(rel2->relids, ec->ec_relids));
3177
3178 /*
3179 * Won't generate joinclauses if single-member (this test covers the
3180 * volatile case too)
3181 */
3182 if (list_length(ec->ec_members) <= 1)
3183 continue;
3184
3185 /*
3186 * We do not need to examine the individual members of the EC, because
3187 * all that we care about is whether each rel overlaps the relids of
3188 * at least one member, and get_common_eclass_indexes() and the single
3189 * member check above are sufficient to prove that. (As with
3190 * have_relevant_joinclause(), it is not necessary that the EC be able
3191 * to form a joinclause relating exactly the two given rels, only that
3192 * it be able to form a joinclause mentioning both, and this will
3193 * surely be true if both of them overlap ec_relids.)
3194 *
3195 * Note we don't test ec_broken; if we did, we'd need a separate code
3196 * path to look through ec_sources. Checking the membership anyway is
3197 * OK as a possibly-overoptimistic heuristic.
3198 *
3199 * We don't test ec_has_const either, even though a const eclass won't
3200 * generate real join clauses. This is because if we had "WHERE a.x =
3201 * b.y and a.x = 42", it is worth considering a join between a and b,
3202 * since the join result is likely to be small even though it'll end
3203 * up being an unqualified nestloop.
3204 */
3205
3206 return true;
3207 }
3208
3209 return false;
3210}

References Assert, bms_next_member(), bms_overlap(), EquivalenceClass::ec_members, EquivalenceClass::ec_relids, get_common_eclass_indexes(), i, list_length(), list_nth(), RelOptInfo::relids, and root.

Referenced by have_relevant_joinclause().

◆ is_redundant_derived_clause()

bool is_redundant_derived_clause ( RestrictInfo rinfo,
List clauselist 
)

Definition at line 3324 of file equivclass.c.

3325{
3326 EquivalenceClass *parent_ec = rinfo->parent_ec;
3327 ListCell *lc;
3328
3329 /* Fail if it's not a potentially-redundant clause from some EC */
3330 if (parent_ec == NULL)
3331 return false;
3332
3333 foreach(lc, clauselist)
3334 {
3335 RestrictInfo *otherrinfo = (RestrictInfo *) lfirst(lc);
3336
3337 if (otherrinfo->parent_ec == parent_ec)
3338 return true;
3339 }
3340
3341 return false;
3342}

References lfirst.

Referenced by create_tidscan_plan().

◆ is_redundant_with_indexclauses()

bool is_redundant_with_indexclauses ( RestrictInfo rinfo,
List indexclauses 
)

Definition at line 3351 of file equivclass.c.

3352{
3353 EquivalenceClass *parent_ec = rinfo->parent_ec;
3354 ListCell *lc;
3355
3356 foreach(lc, indexclauses)
3357 {
3358 IndexClause *iclause = lfirst_node(IndexClause, lc);
3359 RestrictInfo *otherrinfo = iclause->rinfo;
3360
3361 /* If indexclause is lossy, it won't enforce the condition exactly */
3362 if (iclause->lossy)
3363 continue;
3364
3365 /* Match if it's same clause (pointer equality should be enough) */
3366 if (rinfo == otherrinfo)
3367 return true;
3368 /* Match if derived from same EC */
3369 if (parent_ec && otherrinfo->parent_ec == parent_ec)
3370 return true;
3371
3372 /*
3373 * No need to look at the derived clauses in iclause->indexquals; they
3374 * couldn't match if the parent clause didn't.
3375 */
3376 }
3377
3378 return false;
3379}
struct RestrictInfo * rinfo
Definition: pathnodes.h:1789

References lfirst_node, IndexClause::lossy, and IndexClause::rinfo.

Referenced by create_indexscan_plan(), extract_nonindex_conditions(), and has_indexed_join_quals().

◆ match_eclasses_to_foreign_key_col()

EquivalenceClass * match_eclasses_to_foreign_key_col ( PlannerInfo root,
ForeignKeyOptInfo fkinfo,
int  colno 
)

Definition at line 2559 of file equivclass.c.

2562{
2563 Index var1varno = fkinfo->con_relid;
2564 AttrNumber var1attno = fkinfo->conkey[colno];
2565 Index var2varno = fkinfo->ref_relid;
2566 AttrNumber var2attno = fkinfo->confkey[colno];
2567 Oid eqop = fkinfo->conpfeqop[colno];
2568 RelOptInfo *rel1 = root->simple_rel_array[var1varno];
2569 RelOptInfo *rel2 = root->simple_rel_array[var2varno];
2570 List *opfamilies = NIL; /* compute only if needed */
2571 Bitmapset *matching_ecs;
2572 int i;
2573
2574 /* Consider only eclasses mentioning both relations */
2575 Assert(root->ec_merging_done);
2576 Assert(IS_SIMPLE_REL(rel1));
2577 Assert(IS_SIMPLE_REL(rel2));
2578 matching_ecs = bms_intersect(rel1->eclass_indexes,
2579 rel2->eclass_indexes);
2580
2581 i = -1;
2582 while ((i = bms_next_member(matching_ecs, i)) >= 0)
2583 {
2584 EquivalenceClass *ec = (EquivalenceClass *) list_nth(root->eq_classes,
2585 i);
2586 EquivalenceMember *item1_em = NULL;
2587 EquivalenceMember *item2_em = NULL;
2588 ListCell *lc2;
2589
2590 /* Never match to a volatile EC */
2591 if (ec->ec_has_volatile)
2592 continue;
2593 /* It's okay to consider "broken" ECs here, see exprs_known_equal */
2594
2595 foreach(lc2, ec->ec_members)
2596 {
2598 Var *var;
2599
2600 if (em->em_is_child)
2601 continue; /* ignore children here */
2602
2603 /* EM must be a Var, possibly with RelabelType */
2604 var = (Var *) em->em_expr;
2605 while (var && IsA(var, RelabelType))
2606 var = (Var *) ((RelabelType *) var)->arg;
2607 if (!(var && IsA(var, Var)))
2608 continue;
2609
2610 /* Match? */
2611 if (var->varno == var1varno && var->varattno == var1attno)
2612 item1_em = em;
2613 else if (var->varno == var2varno && var->varattno == var2attno)
2614 item2_em = em;
2615
2616 /* Have we found both PK and FK column in this EC? */
2617 if (item1_em && item2_em)
2618 {
2619 /*
2620 * Succeed if eqop matches EC's opfamilies. We could test
2621 * this before scanning the members, but it's probably cheaper
2622 * to test for member matches first.
2623 */
2624 if (opfamilies == NIL) /* compute if we didn't already */
2625 opfamilies = get_mergejoin_opfamilies(eqop);
2626 if (equal(opfamilies, ec->ec_opfamilies))
2627 {
2628 fkinfo->eclass[colno] = ec;
2629 fkinfo->fk_eclass_member[colno] = item2_em;
2630 return ec;
2631 }
2632 /* Otherwise, done with this EC, move on to the next */
2633 break;
2634 }
2635 }
2636 }
2637 return NULL;
2638}
int16 AttrNumber
Definition: attnum.h:21
Bitmapset * bms_intersect(const Bitmapset *a, const Bitmapset *b)
Definition: bitmapset.c:292
unsigned int Index
Definition: c.h:571
List * get_mergejoin_opfamilies(Oid opno)
Definition: lsyscache.c:367
while(p+4<=pend)
struct EquivalenceClass * eclass[INDEX_MAX_KEYS]
Definition: pathnodes.h:1280
struct EquivalenceMember * fk_eclass_member[INDEX_MAX_KEYS]
Definition: pathnodes.h:1282
AttrNumber varattno
Definition: primnodes.h:274
int varno
Definition: primnodes.h:269

References Assert, bms_intersect(), bms_next_member(), ForeignKeyOptInfo::con_relid, EquivalenceClass::ec_has_volatile, EquivalenceClass::ec_members, EquivalenceClass::ec_opfamilies, ForeignKeyOptInfo::eclass, RelOptInfo::eclass_indexes, EquivalenceMember::em_expr, EquivalenceMember::em_is_child, equal(), ForeignKeyOptInfo::fk_eclass_member, get_mergejoin_opfamilies(), i, IS_SIMPLE_REL, IsA, lfirst, list_nth(), NIL, ForeignKeyOptInfo::ref_relid, root, Var::varattno, Var::varno, and while().

Referenced by match_foreign_keys_to_quals().

◆ process_equivalence()

bool process_equivalence ( PlannerInfo root,
RestrictInfo **  p_restrictinfo,
JoinDomain jdomain 
)

Definition at line 117 of file equivclass.c.

120{
121 RestrictInfo *restrictinfo = *p_restrictinfo;
122 Expr *clause = restrictinfo->clause;
123 Oid opno,
124 collation,
125 item1_type,
126 item2_type;
127 Expr *item1;
128 Expr *item2;
129 Relids item1_relids,
130 item2_relids;
131 List *opfamilies;
132 EquivalenceClass *ec1,
133 *ec2;
135 *em2;
136 ListCell *lc1;
137 int ec2_idx;
138
139 /* Should not already be marked as having generated an eclass */
140 Assert(restrictinfo->left_ec == NULL);
141 Assert(restrictinfo->right_ec == NULL);
142
143 /* Reject if it is potentially postponable by security considerations */
144 if (restrictinfo->security_level > 0 && !restrictinfo->leakproof)
145 return false;
146
147 /* Extract info from given clause */
148 Assert(is_opclause(clause));
149 opno = ((OpExpr *) clause)->opno;
150 collation = ((OpExpr *) clause)->inputcollid;
151 item1 = (Expr *) get_leftop(clause);
152 item2 = (Expr *) get_rightop(clause);
153 item1_relids = restrictinfo->left_relids;
154 item2_relids = restrictinfo->right_relids;
155
156 /*
157 * Ensure both input expressions expose the desired collation (their types
158 * should be OK already); see comments for canonicalize_ec_expression.
159 */
160 item1 = canonicalize_ec_expression(item1,
161 exprType((Node *) item1),
162 collation);
163 item2 = canonicalize_ec_expression(item2,
164 exprType((Node *) item2),
165 collation);
166
167 /*
168 * Clauses of the form X=X cannot be translated into EquivalenceClasses.
169 * We'd either end up with a single-entry EC, losing the knowledge that
170 * the clause was present at all, or else make an EC with duplicate
171 * entries, causing other issues.
172 */
173 if (equal(item1, item2))
174 {
175 /*
176 * If the operator is strict, then the clause can be treated as just
177 * "X IS NOT NULL". (Since we know we are considering a top-level
178 * qual, we can ignore the difference between FALSE and NULL results.)
179 * It's worth making the conversion because we'll typically get a much
180 * better selectivity estimate than we would for X=X.
181 *
182 * If the operator is not strict, we can't be sure what it will do
183 * with NULLs, so don't attempt to optimize it.
184 */
185 set_opfuncid((OpExpr *) clause);
186 if (func_strict(((OpExpr *) clause)->opfuncid))
187 {
188 NullTest *ntest = makeNode(NullTest);
189
190 ntest->arg = item1;
191 ntest->nulltesttype = IS_NOT_NULL;
192 ntest->argisrow = false; /* correct even if composite arg */
193 ntest->location = -1;
194
195 *p_restrictinfo =
197 (Expr *) ntest,
198 restrictinfo->is_pushed_down,
199 restrictinfo->has_clone,
200 restrictinfo->is_clone,
201 restrictinfo->pseudoconstant,
202 restrictinfo->security_level,
203 NULL,
204 restrictinfo->incompatible_relids,
205 restrictinfo->outer_relids);
206 }
207 return false;
208 }
209
210 /*
211 * We use the declared input types of the operator, not exprType() of the
212 * inputs, as the nominal datatypes for opfamily lookup. This presumes
213 * that btree operators are always registered with amoplefttype and
214 * amoprighttype equal to their declared input types. We will need this
215 * info anyway to build EquivalenceMember nodes, and by extracting it now
216 * we can use type comparisons to short-circuit some equal() tests.
217 */
218 op_input_types(opno, &item1_type, &item2_type);
219
220 opfamilies = restrictinfo->mergeopfamilies;
221
222 /*
223 * Sweep through the existing EquivalenceClasses looking for matches to
224 * item1 and item2. These are the possible outcomes:
225 *
226 * 1. We find both in the same EC. The equivalence is already known, so
227 * there's nothing to do.
228 *
229 * 2. We find both in different ECs. Merge the two ECs together.
230 *
231 * 3. We find just one. Add the other to its EC.
232 *
233 * 4. We find neither. Make a new, two-entry EC.
234 *
235 * Note: since all ECs are built through this process or the similar
236 * search in get_eclass_for_sort_expr(), it's impossible that we'd match
237 * an item in more than one existing nonvolatile EC. So it's okay to stop
238 * at the first match.
239 */
240 ec1 = ec2 = NULL;
241 em1 = em2 = NULL;
242 ec2_idx = -1;
243 foreach(lc1, root->eq_classes)
244 {
245 EquivalenceClass *cur_ec = (EquivalenceClass *) lfirst(lc1);
246 ListCell *lc2;
247
248 /* Never match to a volatile EC */
249 if (cur_ec->ec_has_volatile)
250 continue;
251
252 /*
253 * The collation has to match; check this first since it's cheaper
254 * than the opfamily comparison.
255 */
256 if (collation != cur_ec->ec_collation)
257 continue;
258
259 /*
260 * A "match" requires matching sets of btree opfamilies. Use of
261 * equal() for this test has implications discussed in the comments
262 * for get_mergejoin_opfamilies().
263 */
264 if (!equal(opfamilies, cur_ec->ec_opfamilies))
265 continue;
266
267 foreach(lc2, cur_ec->ec_members)
268 {
269 EquivalenceMember *cur_em = (EquivalenceMember *) lfirst(lc2);
270
271 Assert(!cur_em->em_is_child); /* no children yet */
272
273 /*
274 * Match constants only within the same JoinDomain (see
275 * optimizer/README).
276 */
277 if (cur_em->em_is_const && cur_em->em_jdomain != jdomain)
278 continue;
279
280 if (!ec1 &&
281 item1_type == cur_em->em_datatype &&
282 equal(item1, cur_em->em_expr))
283 {
284 ec1 = cur_ec;
285 em1 = cur_em;
286 if (ec2)
287 break;
288 }
289
290 if (!ec2 &&
291 item2_type == cur_em->em_datatype &&
292 equal(item2, cur_em->em_expr))
293 {
294 ec2 = cur_ec;
295 ec2_idx = foreach_current_index(lc1);
296 em2 = cur_em;
297 if (ec1)
298 break;
299 }
300 }
301
302 if (ec1 && ec2)
303 break;
304 }
305
306 /* Sweep finished, what did we find? */
307
308 if (ec1 && ec2)
309 {
310 /* If case 1, nothing to do, except add to sources */
311 if (ec1 == ec2)
312 {
313 ec1->ec_sources = lappend(ec1->ec_sources, restrictinfo);
315 restrictinfo->security_level);
317 restrictinfo->security_level);
318 /* mark the RI as associated with this eclass */
319 restrictinfo->left_ec = ec1;
320 restrictinfo->right_ec = ec1;
321 /* mark the RI as usable with this pair of EMs */
322 restrictinfo->left_em = em1;
323 restrictinfo->right_em = em2;
324 return true;
325 }
326
327 /*
328 * Case 2: need to merge ec1 and ec2. This should never happen after
329 * the ECs have reached canonical state; otherwise, pathkeys could be
330 * rendered non-canonical by the merge, and relation eclass indexes
331 * would get broken by removal of an eq_classes list entry.
332 */
333 if (root->ec_merging_done)
334 elog(ERROR, "too late to merge equivalence classes");
335
336 /*
337 * We add ec2's items to ec1, then set ec2's ec_merged link to point
338 * to ec1 and remove ec2 from the eq_classes list. We cannot simply
339 * delete ec2 because that could leave dangling pointers in existing
340 * PathKeys. We leave it behind with a link so that the merged EC can
341 * be found.
342 */
343 ec1->ec_members = list_concat(ec1->ec_members, ec2->ec_members);
344 ec1->ec_sources = list_concat(ec1->ec_sources, ec2->ec_sources);
345 ec1->ec_derives = list_concat(ec1->ec_derives, ec2->ec_derives);
346 ec1->ec_relids = bms_join(ec1->ec_relids, ec2->ec_relids);
347 ec1->ec_has_const |= ec2->ec_has_const;
348 /* can't need to set has_volatile */
350 ec2->ec_min_security);
352 ec2->ec_max_security);
353 ec2->ec_merged = ec1;
354 root->eq_classes = list_delete_nth_cell(root->eq_classes, ec2_idx);
355 /* just to avoid debugging confusion w/ dangling pointers: */
356 ec2->ec_members = NIL;
357 ec2->ec_sources = NIL;
358 ec2->ec_derives = NIL;
359 ec2->ec_relids = NULL;
360 ec1->ec_sources = lappend(ec1->ec_sources, restrictinfo);
362 restrictinfo->security_level);
364 restrictinfo->security_level);
365 /* mark the RI as associated with this eclass */
366 restrictinfo->left_ec = ec1;
367 restrictinfo->right_ec = ec1;
368 /* mark the RI as usable with this pair of EMs */
369 restrictinfo->left_em = em1;
370 restrictinfo->right_em = em2;
371 }
372 else if (ec1)
373 {
374 /* Case 3: add item2 to ec1 */
375 em2 = add_eq_member(ec1, item2, item2_relids,
376 jdomain, NULL, item2_type);
377 ec1->ec_sources = lappend(ec1->ec_sources, restrictinfo);
379 restrictinfo->security_level);
381 restrictinfo->security_level);
382 /* mark the RI as associated with this eclass */
383 restrictinfo->left_ec = ec1;
384 restrictinfo->right_ec = ec1;
385 /* mark the RI as usable with this pair of EMs */
386 restrictinfo->left_em = em1;
387 restrictinfo->right_em = em2;
388 }
389 else if (ec2)
390 {
391 /* Case 3: add item1 to ec2 */
392 em1 = add_eq_member(ec2, item1, item1_relids,
393 jdomain, NULL, item1_type);
394 ec2->ec_sources = lappend(ec2->ec_sources, restrictinfo);
396 restrictinfo->security_level);
398 restrictinfo->security_level);
399 /* mark the RI as associated with this eclass */
400 restrictinfo->left_ec = ec2;
401 restrictinfo->right_ec = ec2;
402 /* mark the RI as usable with this pair of EMs */
403 restrictinfo->left_em = em1;
404 restrictinfo->right_em = em2;
405 }
406 else
407 {
408 /* Case 4: make a new, two-entry EC */
410
411 ec->ec_opfamilies = opfamilies;
412 ec->ec_collation = collation;
413 ec->ec_members = NIL;
414 ec->ec_sources = list_make1(restrictinfo);
415 ec->ec_derives = NIL;
416 ec->ec_relids = NULL;
417 ec->ec_has_const = false;
418 ec->ec_has_volatile = false;
419 ec->ec_broken = false;
420 ec->ec_sortref = 0;
421 ec->ec_min_security = restrictinfo->security_level;
422 ec->ec_max_security = restrictinfo->security_level;
423 ec->ec_merged = NULL;
424 em1 = add_eq_member(ec, item1, item1_relids,
425 jdomain, NULL, item1_type);
426 em2 = add_eq_member(ec, item2, item2_relids,
427 jdomain, NULL, item2_type);
428
429 root->eq_classes = lappend(root->eq_classes, ec);
430
431 /* mark the RI as associated with this eclass */
432 restrictinfo->left_ec = ec;
433 restrictinfo->right_ec = ec;
434 /* mark the RI as usable with this pair of EMs */
435 restrictinfo->left_em = em1;
436 restrictinfo->right_em = em2;
437 }
438
439 return true;
440}
Bitmapset * bms_join(Bitmapset *a, Bitmapset *b)
Definition: bitmapset.c:1230
#define Min(x, y)
Definition: c.h:961
#define Max(x, y)
Definition: c.h:955
List * list_delete_nth_cell(List *list, int n)
Definition: list.c:767
bool func_strict(Oid funcid)
Definition: lsyscache.c:1788
void op_input_types(Oid opno, Oid *lefttype, Oid *righttype)
Definition: lsyscache.c:1385
void set_opfuncid(OpExpr *opexpr)
Definition: nodeFuncs.c:1872
static Node * get_rightop(const void *clause)
Definition: nodeFuncs.h:95
static bool is_opclause(const void *clause)
Definition: nodeFuncs.h:76
static Node * get_leftop(const void *clause)
Definition: nodeFuncs.h:83
#define foreach_current_index(var_or_cell)
Definition: pg_list.h:403
#define list_make1(x1)
Definition: pg_list.h:212
@ IS_NOT_NULL
Definition: primnodes.h:1957
RestrictInfo * make_restrictinfo(PlannerInfo *root, Expr *clause, bool is_pushed_down, bool has_clone, bool is_clone, bool pseudoconstant, Index security_level, Relids required_relids, Relids incompatible_relids, Relids outer_relids)
Definition: restrictinfo.c:52
NullTestType nulltesttype
Definition: primnodes.h:1964
ParseLoc location
Definition: primnodes.h:1967
Expr * arg
Definition: primnodes.h:1963
bool is_pushed_down
Definition: pathnodes.h:2597
Index security_level
Definition: pathnodes.h:2616
Relids outer_relids
Definition: pathnodes.h:2631
Relids incompatible_relids
Definition: pathnodes.h:2628
Expr * clause
Definition: pathnodes.h:2594
bool has_clone
Definition: pathnodes.h:2606

References add_eq_member(), NullTest::arg, Assert, bms_join(), canonicalize_ec_expression(), RestrictInfo::clause, EquivalenceClass::ec_broken, EquivalenceClass::ec_collation, EquivalenceClass::ec_derives, EquivalenceClass::ec_has_const, EquivalenceClass::ec_has_volatile, EquivalenceClass::ec_max_security, EquivalenceClass::ec_members, EquivalenceClass::ec_merged, EquivalenceClass::ec_min_security, EquivalenceClass::ec_opfamilies, EquivalenceClass::ec_relids, EquivalenceClass::ec_sortref, EquivalenceClass::ec_sources, elog, EquivalenceMember::em_datatype, EquivalenceMember::em_expr, EquivalenceMember::em_is_child, EquivalenceMember::em_is_const, EquivalenceMember::em_jdomain, equal(), ERROR, exprType(), foreach_current_index, func_strict(), get_leftop(), get_rightop(), RestrictInfo::has_clone, RestrictInfo::incompatible_relids, RestrictInfo::is_clone, IS_NOT_NULL, is_opclause(), RestrictInfo::is_pushed_down, lappend(), lfirst, list_concat(), list_delete_nth_cell(), list_make1, NullTest::location, make_restrictinfo(), makeNode, Max, Min, NIL, NullTest::nulltesttype, op_input_types(), RestrictInfo::outer_relids, root, RestrictInfo::security_level, and set_opfuncid().

Referenced by distribute_qual_to_rels(), reconsider_full_join_clause(), and reconsider_outer_join_clause().

◆ rebuild_eclass_attr_needed()

void rebuild_eclass_attr_needed ( PlannerInfo root)

Definition at line 2431 of file equivclass.c.

2432{
2433 ListCell *lc;
2434
2435 foreach(lc, root->eq_classes)
2436 {
2438
2439 /* Need do anything only for a multi-member, no-const EC. */
2440 if (list_length(ec->ec_members) > 1 && !ec->ec_has_const)
2441 {
2442 ListCell *lc2;
2443
2444 foreach(lc2, ec->ec_members)
2445 {
2446 EquivalenceMember *cur_em = (EquivalenceMember *) lfirst(lc2);
2447 List *vars = pull_var_clause((Node *) cur_em->em_expr,
2451
2453 list_free(vars);
2454 }
2455 }
2456 }
2457}
void add_vars_to_attr_needed(PlannerInfo *root, List *vars, Relids where_needed)
Definition: initsplan.c:353

References add_vars_to_attr_needed(), EquivalenceClass::ec_has_const, EquivalenceClass::ec_members, EquivalenceClass::ec_relids, EquivalenceMember::em_expr, lfirst, list_free(), list_length(), pull_var_clause(), PVC_INCLUDE_PLACEHOLDERS, PVC_RECURSE_AGGREGATES, PVC_RECURSE_WINDOWFUNCS, and root.

Referenced by remove_rel_from_query().

◆ reconsider_full_join_clause()

static bool reconsider_full_join_clause ( PlannerInfo root,
OuterJoinClauseInfo ojcinfo 
)
static

Definition at line 2246 of file equivclass.c.

2247{
2248 RestrictInfo *rinfo = ojcinfo->rinfo;
2249 SpecialJoinInfo *sjinfo = ojcinfo->sjinfo;
2250 Relids fjrelids = bms_make_singleton(sjinfo->ojrelid);
2251 Expr *leftvar;
2252 Expr *rightvar;
2253 Oid opno,
2254 collation,
2255 left_type,
2256 right_type;
2257 Relids left_relids,
2258 right_relids;
2259 ListCell *lc1;
2260
2261 /* Extract needed info from the clause */
2262 Assert(is_opclause(rinfo->clause));
2263 opno = ((OpExpr *) rinfo->clause)->opno;
2264 collation = ((OpExpr *) rinfo->clause)->inputcollid;
2265 op_input_types(opno, &left_type, &right_type);
2266 leftvar = (Expr *) get_leftop(rinfo->clause);
2267 rightvar = (Expr *) get_rightop(rinfo->clause);
2268 left_relids = rinfo->left_relids;
2269 right_relids = rinfo->right_relids;
2270
2271 foreach(lc1, root->eq_classes)
2272 {
2273 EquivalenceClass *cur_ec = (EquivalenceClass *) lfirst(lc1);
2274 EquivalenceMember *coal_em = NULL;
2275 bool match;
2276 bool matchleft;
2277 bool matchright;
2278 ListCell *lc2;
2279 int coal_idx = -1;
2280
2281 /* Ignore EC unless it contains pseudoconstants */
2282 if (!cur_ec->ec_has_const)
2283 continue;
2284 /* Never match to a volatile EC */
2285 if (cur_ec->ec_has_volatile)
2286 continue;
2287 /* It has to match the outer-join clause as to semantics, too */
2288 if (collation != cur_ec->ec_collation)
2289 continue;
2290 if (!equal(rinfo->mergeopfamilies, cur_ec->ec_opfamilies))
2291 continue;
2292
2293 /*
2294 * Does it contain a COALESCE(leftvar, rightvar) construct?
2295 *
2296 * We can assume the COALESCE() inputs are in the same order as the
2297 * join clause, since both were automatically generated in the cases
2298 * we care about.
2299 *
2300 * XXX currently this may fail to match in cross-type cases because
2301 * the COALESCE will contain typecast operations while the join clause
2302 * may not (if there is a cross-type mergejoin operator available for
2303 * the two column types). Is it OK to strip implicit coercions from
2304 * the COALESCE arguments?
2305 */
2306 match = false;
2307 foreach(lc2, cur_ec->ec_members)
2308 {
2309 coal_em = (EquivalenceMember *) lfirst(lc2);
2310 Assert(!coal_em->em_is_child); /* no children yet */
2311 if (IsA(coal_em->em_expr, CoalesceExpr))
2312 {
2313 CoalesceExpr *cexpr = (CoalesceExpr *) coal_em->em_expr;
2314 Node *cfirst;
2315 Node *csecond;
2316
2317 if (list_length(cexpr->args) != 2)
2318 continue;
2319 cfirst = (Node *) linitial(cexpr->args);
2320 csecond = (Node *) lsecond(cexpr->args);
2321
2322 /*
2323 * The COALESCE arguments will be marked as possibly nulled by
2324 * the full join, while we wish to generate clauses that apply
2325 * to the join's inputs. So we must strip the join from the
2326 * nullingrels fields of cfirst/csecond before comparing them
2327 * to leftvar/rightvar. (Perhaps with a less hokey
2328 * representation for FULL JOIN USING output columns, this
2329 * wouldn't be needed?)
2330 */
2331 cfirst = remove_nulling_relids(cfirst, fjrelids, NULL);
2332 csecond = remove_nulling_relids(csecond, fjrelids, NULL);
2333
2334 if (equal(leftvar, cfirst) && equal(rightvar, csecond))
2335 {
2336 coal_idx = foreach_current_index(lc2);
2337 match = true;
2338 break;
2339 }
2340 }
2341 }
2342 if (!match)
2343 continue; /* no match, so ignore this EC */
2344
2345 /*
2346 * Yes it does! Try to generate clauses LEFTVAR = CONSTANT and
2347 * RIGHTVAR = CONSTANT for each CONSTANT in the EC. Note that we must
2348 * succeed with at least one constant for each var before we can
2349 * decide to throw away the outer-join clause.
2350 */
2351 matchleft = matchright = false;
2352 foreach(lc2, cur_ec->ec_members)
2353 {
2354 EquivalenceMember *cur_em = (EquivalenceMember *) lfirst(lc2);
2355 Oid eq_op;
2356 RestrictInfo *newrinfo;
2357 JoinDomain *jdomain;
2358
2359 if (!cur_em->em_is_const)
2360 continue; /* ignore non-const members */
2361 eq_op = select_equality_operator(cur_ec,
2362 left_type,
2363 cur_em->em_datatype);
2364 if (OidIsValid(eq_op))
2365 {
2367 eq_op,
2368 cur_ec->ec_collation,
2369 leftvar,
2370 cur_em->em_expr,
2371 bms_copy(left_relids),
2372 cur_ec->ec_min_security);
2373 /* This equality holds within the lefthand child JoinDomain */
2374 jdomain = find_join_domain(root, sjinfo->syn_lefthand);
2375 if (process_equivalence(root, &newrinfo, jdomain))
2376 matchleft = true;
2377 }
2378 eq_op = select_equality_operator(cur_ec,
2379 right_type,
2380 cur_em->em_datatype);
2381 if (OidIsValid(eq_op))
2382 {
2384 eq_op,
2385 cur_ec->ec_collation,
2386 rightvar,
2387 cur_em->em_expr,
2388 bms_copy(right_relids),
2389 cur_ec->ec_min_security);
2390 /* This equality holds within the righthand child JoinDomain */
2391 jdomain = find_join_domain(root, sjinfo->syn_righthand);
2392 if (process_equivalence(root, &newrinfo, jdomain))
2393 matchright = true;
2394 }
2395 }
2396
2397 /*
2398 * If we were able to equate both vars to constants, we're done, and
2399 * we can throw away the full-join clause as redundant. Moreover, we
2400 * can remove the COALESCE entry from the EC, since the added
2401 * restrictions ensure it will always have the expected value. (We
2402 * don't bother trying to update ec_relids or ec_sources.)
2403 */
2404 if (matchleft && matchright)
2405 {
2406 cur_ec->ec_members = list_delete_nth_cell(cur_ec->ec_members, coal_idx);
2407 return true;
2408 }
2409
2410 /*
2411 * Otherwise, fall out of the search loop, since we know the COALESCE
2412 * appears in at most one EC (XXX might stop being true if we allow
2413 * stripping of coercions above?)
2414 */
2415 break;
2416 }
2417
2418 return false; /* failed to make any deduction */
2419}
Bitmapset * bms_make_singleton(int x)
Definition: bitmapset.c:216
Bitmapset * bms_copy(const Bitmapset *a)
Definition: bitmapset.c:122
static JoinDomain * find_join_domain(PlannerInfo *root, Relids relids)
Definition: equivclass.c:2467
bool process_equivalence(PlannerInfo *root, RestrictInfo **p_restrictinfo, JoinDomain *jdomain)
Definition: equivclass.c:117
if(TABLE==NULL||TABLE_index==NULL)
Definition: isn.c:76
#define lsecond(l)
Definition: pg_list.h:183
Node * remove_nulling_relids(Node *node, const Bitmapset *removable_relids, const Bitmapset *except_relids)
List * args
Definition: primnodes.h:1497
RestrictInfo * rinfo
Definition: pathnodes.h:2953
SpecialJoinInfo * sjinfo
Definition: pathnodes.h:2954
Relids syn_lefthand
Definition: pathnodes.h:2926
Relids syn_righthand
Definition: pathnodes.h:2927

References CoalesceExpr::args, Assert, bms_copy(), bms_make_singleton(), build_implied_join_equality(), RestrictInfo::clause, EquivalenceClass::ec_collation, EquivalenceClass::ec_has_const, EquivalenceClass::ec_has_volatile, EquivalenceClass::ec_members, EquivalenceClass::ec_min_security, EquivalenceClass::ec_opfamilies, EquivalenceMember::em_datatype, EquivalenceMember::em_expr, EquivalenceMember::em_is_child, EquivalenceMember::em_is_const, equal(), find_join_domain(), foreach_current_index, get_leftop(), get_rightop(), if(), is_opclause(), IsA, lfirst, linitial, list_delete_nth_cell(), list_length(), lsecond, OidIsValid, SpecialJoinInfo::ojrelid, op_input_types(), process_equivalence(), remove_nulling_relids(), OuterJoinClauseInfo::rinfo, root, select_equality_operator(), OuterJoinClauseInfo::sjinfo, SpecialJoinInfo::syn_lefthand, and SpecialJoinInfo::syn_righthand.

Referenced by reconsider_outer_join_clauses().

◆ reconsider_outer_join_clause()

static bool reconsider_outer_join_clause ( PlannerInfo root,
OuterJoinClauseInfo ojcinfo,
bool  outer_on_left 
)
static

Definition at line 2123 of file equivclass.c.

2125{
2126 RestrictInfo *rinfo = ojcinfo->rinfo;
2127 SpecialJoinInfo *sjinfo = ojcinfo->sjinfo;
2128 Expr *outervar,
2129 *innervar;
2130 Oid opno,
2131 collation,
2132 left_type,
2133 right_type,
2134 inner_datatype;
2135 Relids inner_relids;
2136 ListCell *lc1;
2137
2138 Assert(is_opclause(rinfo->clause));
2139 opno = ((OpExpr *) rinfo->clause)->opno;
2140 collation = ((OpExpr *) rinfo->clause)->inputcollid;
2141
2142 /* Extract needed info from the clause */
2143 op_input_types(opno, &left_type, &right_type);
2144 if (outer_on_left)
2145 {
2146 outervar = (Expr *) get_leftop(rinfo->clause);
2147 innervar = (Expr *) get_rightop(rinfo->clause);
2148 inner_datatype = right_type;
2149 inner_relids = rinfo->right_relids;
2150 }
2151 else
2152 {
2153 outervar = (Expr *) get_rightop(rinfo->clause);
2154 innervar = (Expr *) get_leftop(rinfo->clause);
2155 inner_datatype = left_type;
2156 inner_relids = rinfo->left_relids;
2157 }
2158
2159 /* Scan EquivalenceClasses for a match to outervar */
2160 foreach(lc1, root->eq_classes)
2161 {
2162 EquivalenceClass *cur_ec = (EquivalenceClass *) lfirst(lc1);
2163 bool match;
2164 ListCell *lc2;
2165
2166 /* Ignore EC unless it contains pseudoconstants */
2167 if (!cur_ec->ec_has_const)
2168 continue;
2169 /* Never match to a volatile EC */
2170 if (cur_ec->ec_has_volatile)
2171 continue;
2172 /* It has to match the outer-join clause as to semantics, too */
2173 if (collation != cur_ec->ec_collation)
2174 continue;
2175 if (!equal(rinfo->mergeopfamilies, cur_ec->ec_opfamilies))
2176 continue;
2177 /* Does it contain a match to outervar? */
2178 match = false;
2179 foreach(lc2, cur_ec->ec_members)
2180 {
2181 EquivalenceMember *cur_em = (EquivalenceMember *) lfirst(lc2);
2182
2183 Assert(!cur_em->em_is_child); /* no children yet */
2184 if (equal(outervar, cur_em->em_expr))
2185 {
2186 match = true;
2187 break;
2188 }
2189 }
2190 if (!match)
2191 continue; /* no match, so ignore this EC */
2192
2193 /*
2194 * Yes it does! Try to generate a clause INNERVAR = CONSTANT for each
2195 * CONSTANT in the EC. Note that we must succeed with at least one
2196 * constant before we can decide to throw away the outer-join clause.
2197 */
2198 match = false;
2199 foreach(lc2, cur_ec->ec_members)
2200 {
2201 EquivalenceMember *cur_em = (EquivalenceMember *) lfirst(lc2);
2202 Oid eq_op;
2203 RestrictInfo *newrinfo;
2204 JoinDomain *jdomain;
2205
2206 if (!cur_em->em_is_const)
2207 continue; /* ignore non-const members */
2208 eq_op = select_equality_operator(cur_ec,
2209 inner_datatype,
2210 cur_em->em_datatype);
2211 if (!OidIsValid(eq_op))
2212 continue; /* can't generate equality */
2214 eq_op,
2215 cur_ec->ec_collation,
2216 innervar,
2217 cur_em->em_expr,
2218 bms_copy(inner_relids),
2219 cur_ec->ec_min_security);
2220 /* This equality holds within the OJ's child JoinDomain */
2221 jdomain = find_join_domain(root, sjinfo->syn_righthand);
2222 if (process_equivalence(root, &newrinfo, jdomain))
2223 match = true;
2224 }
2225
2226 /*
2227 * If we were able to equate INNERVAR to any constant, report success.
2228 * Otherwise, fall out of the search loop, since we know the OUTERVAR
2229 * appears in at most one EC.
2230 */
2231 if (match)
2232 return true;
2233 else
2234 break;
2235 }
2236
2237 return false; /* failed to make any deduction */
2238}

References Assert, bms_copy(), build_implied_join_equality(), RestrictInfo::clause, EquivalenceClass::ec_collation, EquivalenceClass::ec_has_const, EquivalenceClass::ec_has_volatile, EquivalenceClass::ec_members, EquivalenceClass::ec_min_security, EquivalenceClass::ec_opfamilies, EquivalenceMember::em_datatype, EquivalenceMember::em_expr, EquivalenceMember::em_is_child, EquivalenceMember::em_is_const, equal(), find_join_domain(), get_leftop(), get_rightop(), is_opclause(), lfirst, OidIsValid, op_input_types(), process_equivalence(), OuterJoinClauseInfo::rinfo, root, select_equality_operator(), OuterJoinClauseInfo::sjinfo, and SpecialJoinInfo::syn_righthand.

Referenced by reconsider_outer_join_clauses().

◆ reconsider_outer_join_clauses()

void reconsider_outer_join_clauses ( PlannerInfo root)

Definition at line 2001 of file equivclass.c.

2002{
2003 bool found;
2004 ListCell *cell;
2005
2006 /* Outer loop repeats until we find no more deductions */
2007 do
2008 {
2009 found = false;
2010
2011 /* Process the LEFT JOIN clauses */
2012 foreach(cell, root->left_join_clauses)
2013 {
2014 OuterJoinClauseInfo *ojcinfo = (OuterJoinClauseInfo *) lfirst(cell);
2015
2016 if (reconsider_outer_join_clause(root, ojcinfo, true))
2017 {
2018 RestrictInfo *rinfo = ojcinfo->rinfo;
2019
2020 found = true;
2021 /* remove it from the list */
2022 root->left_join_clauses =
2023 foreach_delete_current(root->left_join_clauses, cell);
2024 /* throw back a dummy replacement clause (see notes above) */
2025 rinfo = make_restrictinfo(root,
2026 (Expr *) makeBoolConst(true, false),
2027 rinfo->is_pushed_down,
2028 rinfo->has_clone,
2029 rinfo->is_clone,
2030 false, /* pseudoconstant */
2031 0, /* security_level */
2032 rinfo->required_relids,
2033 rinfo->incompatible_relids,
2034 rinfo->outer_relids);
2036 }
2037 }
2038
2039 /* Process the RIGHT JOIN clauses */
2040 foreach(cell, root->right_join_clauses)
2041 {
2042 OuterJoinClauseInfo *ojcinfo = (OuterJoinClauseInfo *) lfirst(cell);
2043
2044 if (reconsider_outer_join_clause(root, ojcinfo, false))
2045 {
2046 RestrictInfo *rinfo = ojcinfo->rinfo;
2047
2048 found = true;
2049 /* remove it from the list */
2050 root->right_join_clauses =
2051 foreach_delete_current(root->right_join_clauses, cell);
2052 /* throw back a dummy replacement clause (see notes above) */
2053 rinfo = make_restrictinfo(root,
2054 (Expr *) makeBoolConst(true, false),
2055 rinfo->is_pushed_down,
2056 rinfo->has_clone,
2057 rinfo->is_clone,
2058 false, /* pseudoconstant */
2059 0, /* security_level */
2060 rinfo->required_relids,
2061 rinfo->incompatible_relids,
2062 rinfo->outer_relids);
2064 }
2065 }
2066
2067 /* Process the FULL JOIN clauses */
2068 foreach(cell, root->full_join_clauses)
2069 {
2070 OuterJoinClauseInfo *ojcinfo = (OuterJoinClauseInfo *) lfirst(cell);
2071
2072 if (reconsider_full_join_clause(root, ojcinfo))
2073 {
2074 RestrictInfo *rinfo = ojcinfo->rinfo;
2075
2076 found = true;
2077 /* remove it from the list */
2078 root->full_join_clauses =
2079 foreach_delete_current(root->full_join_clauses, cell);
2080 /* throw back a dummy replacement clause (see notes above) */
2081 rinfo = make_restrictinfo(root,
2082 (Expr *) makeBoolConst(true, false),
2083 rinfo->is_pushed_down,
2084 rinfo->has_clone,
2085 rinfo->is_clone,
2086 false, /* pseudoconstant */
2087 0, /* security_level */
2088 rinfo->required_relids,
2089 rinfo->incompatible_relids,
2090 rinfo->outer_relids);
2092 }
2093 }
2094 } while (found);
2095
2096 /* Now, any remaining clauses have to be thrown back */
2097 foreach(cell, root->left_join_clauses)
2098 {
2099 OuterJoinClauseInfo *ojcinfo = (OuterJoinClauseInfo *) lfirst(cell);
2100
2102 }
2103 foreach(cell, root->right_join_clauses)
2104 {
2105 OuterJoinClauseInfo *ojcinfo = (OuterJoinClauseInfo *) lfirst(cell);
2106
2108 }
2109 foreach(cell, root->full_join_clauses)
2110 {
2111 OuterJoinClauseInfo *ojcinfo = (OuterJoinClauseInfo *) lfirst(cell);
2112
2114 }
2115}
static bool reconsider_outer_join_clause(PlannerInfo *root, OuterJoinClauseInfo *ojcinfo, bool outer_on_left)
Definition: equivclass.c:2123
static bool reconsider_full_join_clause(PlannerInfo *root, OuterJoinClauseInfo *ojcinfo)
Definition: equivclass.c:2246
Node * makeBoolConst(bool value, bool isnull)
Definition: makefuncs.c:361
#define foreach_delete_current(lst, var_or_cell)
Definition: pg_list.h:391

References distribute_restrictinfo_to_rels(), foreach_delete_current, RestrictInfo::has_clone, RestrictInfo::incompatible_relids, RestrictInfo::is_clone, RestrictInfo::is_pushed_down, lfirst, make_restrictinfo(), makeBoolConst(), RestrictInfo::outer_relids, reconsider_full_join_clause(), reconsider_outer_join_clause(), RestrictInfo::required_relids, OuterJoinClauseInfo::rinfo, and root.

Referenced by query_planner().

◆ relation_can_be_sorted_early()

bool relation_can_be_sorted_early ( PlannerInfo root,
RelOptInfo rel,
EquivalenceClass ec,
bool  require_parallel_safe 
)

Definition at line 921 of file equivclass.c.

923{
924 PathTarget *target = rel->reltarget;
926 ListCell *lc;
927
928 /*
929 * Reject volatile ECs immediately; such sorts must always be postponed.
930 */
931 if (ec->ec_has_volatile)
932 return false;
933
934 /*
935 * Try to find an EM directly matching some reltarget member.
936 */
937 foreach(lc, target->exprs)
938 {
939 Expr *targetexpr = (Expr *) lfirst(lc);
940
941 em = find_ec_member_matching_expr(ec, targetexpr, rel->relids);
942 if (!em)
943 continue;
944
945 /*
946 * Reject expressions involving set-returning functions, as those
947 * can't be computed early either. (Note: this test and the following
948 * one are effectively checking properties of targetexpr, so there's
949 * no point in asking whether some other EC member would be better.)
950 */
952 continue;
953
954 /*
955 * If requested, reject expressions that are not parallel-safe. We
956 * check this last because it's a rather expensive test.
957 */
958 if (require_parallel_safe &&
960 continue;
961
962 return true;
963 }
964
965 /*
966 * Try to find an expression computable from the reltarget.
967 */
968 em = find_computable_ec_member(root, ec, target->exprs, rel->relids,
969 require_parallel_safe);
970 if (!em)
971 return false;
972
973 /*
974 * Reject expressions involving set-returning functions, as those can't be
975 * computed early either. (There's no point in looking for another EC
976 * member in this case; since SRFs can't appear in WHERE, they cannot
977 * belong to multi-member ECs.)
978 */
980 return false;
981
982 return true;
983}
EquivalenceMember * find_ec_member_matching_expr(EquivalenceClass *ec, Expr *expr, Relids relids)
Definition: equivclass.c:763
EquivalenceMember * find_computable_ec_member(PlannerInfo *root, EquivalenceClass *ec, List *exprs, Relids relids, bool require_parallel_safe)
Definition: equivclass.c:837
List * exprs
Definition: pathnodes.h:1563
struct PathTarget * reltarget
Definition: pathnodes.h:912

References EquivalenceClass::ec_has_volatile, EquivalenceMember::em_expr, expression_returns_set(), PathTarget::exprs, find_computable_ec_member(), find_ec_member_matching_expr(), is_parallel_safe(), lfirst, RelOptInfo::relids, RelOptInfo::reltarget, and root.

Referenced by get_useful_pathkeys_for_relation().

◆ select_equality_operator()

static Oid select_equality_operator ( EquivalenceClass ec,
Oid  lefttype,
Oid  righttype 
)
static

Definition at line 1781 of file equivclass.c.

1782{
1783 ListCell *lc;
1784
1785 foreach(lc, ec->ec_opfamilies)
1786 {
1787 Oid opfamily = lfirst_oid(lc);
1788 Oid opno;
1789
1790 opno = get_opfamily_member(opfamily, lefttype, righttype,
1792 if (!OidIsValid(opno))
1793 continue;
1794 /* If no barrier quals in query, don't worry about leaky operators */
1795 if (ec->ec_max_security == 0)
1796 return opno;
1797 /* Otherwise, insist that selected operators be leakproof */
1798 if (get_func_leakproof(get_opcode(opno)))
1799 return opno;
1800 }
1801 return InvalidOid;
1802}
RegProcedure get_opcode(Oid opno)
Definition: lsyscache.c:1312
Oid get_opfamily_member(Oid opfamily, Oid lefttype, Oid righttype, int16 strategy)
Definition: lsyscache.c:167
bool get_func_leakproof(Oid funcid)
Definition: lsyscache.c:1864
#define lfirst_oid(lc)
Definition: pg_list.h:174
#define BTEqualStrategyNumber
Definition: stratnum.h:31

References BTEqualStrategyNumber, EquivalenceClass::ec_max_security, EquivalenceClass::ec_opfamilies, get_func_leakproof(), get_opcode(), get_opfamily_member(), InvalidOid, lfirst_oid, and OidIsValid.

Referenced by generate_base_implied_equalities_const(), generate_base_implied_equalities_no_const(), generate_implied_equalities_for_column(), generate_join_implied_equalities_normal(), reconsider_full_join_clause(), and reconsider_outer_join_clause().