diff --git a/contrib/postgres_fdw/postgres_fdw.c b/contrib/postgres_fdw/postgres_fdw.c index b4e0e60928b..a7e0cc9f323 100644 --- a/contrib/postgres_fdw/postgres_fdw.c +++ b/contrib/postgres_fdw/postgres_fdw.c @@ -7847,14 +7847,13 @@ conversion_error_callback(void *arg) EquivalenceMember * find_em_for_rel(PlannerInfo *root, EquivalenceClass *ec, RelOptInfo *rel) { - ListCell *lc; - PgFdwRelationInfo *fpinfo = (PgFdwRelationInfo *) rel->fdw_private; + EquivalenceMemberIterator it; + EquivalenceMember *em; - foreach(lc, ec->ec_members) + setup_eclass_member_iterator(&it, ec, rel->relids); + while ((em = eclass_member_iterator_next(&it)) != NULL) { - EquivalenceMember *em = (EquivalenceMember *) lfirst(lc); - /* * Note we require !bms_is_empty, else we'd accept constant * expressions which are not suitable for the purpose. @@ -7908,7 +7907,10 @@ find_em_for_rel_target(PlannerInfo *root, EquivalenceClass *ec, while (expr && IsA(expr, RelabelType)) expr = ((RelabelType *) expr)->arg; - /* Locate an EquivalenceClass member matching this expr, if any */ + /* + * Locate an EquivalenceClass member matching this expr, if any. + * Ignore child members. + */ foreach(lc2, ec->ec_members) { EquivalenceMember *em = (EquivalenceMember *) lfirst(lc2); @@ -7918,9 +7920,8 @@ find_em_for_rel_target(PlannerInfo *root, EquivalenceClass *ec, if (em->em_is_const) continue; - /* Ignore child members */ - if (em->em_is_child) - continue; + /* Child members should not exist in ec_members */ + Assert(!em->em_is_child); /* Match if same expression (after stripping relabel) */ em_expr = em->em_expr; diff --git a/src/backend/nodes/outfuncs.c b/src/backend/nodes/outfuncs.c index 557f06e344f..ceac3fd8620 100644 --- a/src/backend/nodes/outfuncs.c +++ b/src/backend/nodes/outfuncs.c @@ -465,7 +465,9 @@ _outEquivalenceClass(StringInfo str, const EquivalenceClass *node) WRITE_NODE_FIELD(ec_opfamilies); WRITE_OID_FIELD(ec_collation); + WRITE_INT_FIELD(ec_childmembers_size); WRITE_NODE_FIELD(ec_members); + WRITE_NODE_ARRAY(ec_childmembers, node->ec_childmembers_size); WRITE_NODE_FIELD(ec_sources); /* Only ec_derives_list is written; hash is not serialized. */ WRITE_NODE_FIELD(ec_derives_list); diff --git a/src/backend/optimizer/path/equivclass.c b/src/backend/optimizer/path/equivclass.c index 9cd54c573a8..089f196c958 100644 --- a/src/backend/optimizer/path/equivclass.c +++ b/src/backend/optimizer/path/equivclass.c @@ -34,11 +34,23 @@ #include "utils/lsyscache.h" +static EquivalenceMember *make_eq_member(EquivalenceClass *ec, + Expr *expr, Relids relids, + JoinDomain *jdomain, + EquivalenceMember *parent, + Oid datatype); static EquivalenceMember *add_eq_member(EquivalenceClass *ec, Expr *expr, Relids relids, JoinDomain *jdomain, - EquivalenceMember *parent, Oid datatype); +static EquivalenceMember *add_child_eq_member(PlannerInfo *root, + EquivalenceClass *ec, + int ec_index, Expr *expr, + Relids relids, + JoinDomain *jdomain, + EquivalenceMember *parent_em, + Oid datatype, + Relids child_relids); static void generate_base_implied_equalities_const(PlannerInfo *root, EquivalenceClass *ec); static void generate_base_implied_equalities_no_const(PlannerInfo *root, @@ -314,11 +326,15 @@ process_equivalence(PlannerInfo *root, if (!equal(opfamilies, cur_ec->ec_opfamilies)) continue; + /* We don't expect any children yet */ + Assert(cur_ec->ec_childmembers == NULL); + foreach(lc2, cur_ec->ec_members) { EquivalenceMember *cur_em = (EquivalenceMember *) lfirst(lc2); - Assert(!cur_em->em_is_child); /* no children yet */ + /* Child members should not exist in ec_members */ + Assert(!cur_em->em_is_child); /* * Match constants only within the same JoinDomain (see @@ -428,7 +444,7 @@ process_equivalence(PlannerInfo *root, { /* Case 3: add item2 to ec1 */ em2 = add_eq_member(ec1, item2, item2_relids, - jdomain, NULL, item2_type); + jdomain, item2_type); ec1->ec_sources = lappend(ec1->ec_sources, restrictinfo); ec1->ec_min_security = Min(ec1->ec_min_security, restrictinfo->security_level); @@ -445,7 +461,7 @@ process_equivalence(PlannerInfo *root, { /* Case 3: add item1 to ec2 */ em1 = add_eq_member(ec2, item1, item1_relids, - jdomain, NULL, item1_type); + jdomain, item1_type); ec2->ec_sources = lappend(ec2->ec_sources, restrictinfo); ec2->ec_min_security = Min(ec2->ec_min_security, restrictinfo->security_level); @@ -465,7 +481,9 @@ process_equivalence(PlannerInfo *root, ec->ec_opfamilies = opfamilies; ec->ec_collation = collation; + ec->ec_childmembers_size = 0; ec->ec_members = NIL; + ec->ec_childmembers = NULL; ec->ec_sources = list_make1(restrictinfo); ec->ec_derives_list = NIL; ec->ec_derives_hash = NULL; @@ -478,9 +496,9 @@ process_equivalence(PlannerInfo *root, ec->ec_max_security = restrictinfo->security_level; ec->ec_merged = NULL; em1 = add_eq_member(ec, item1, item1_relids, - jdomain, NULL, item1_type); + jdomain, item1_type); em2 = add_eq_member(ec, item2, item2_relids, - jdomain, NULL, item2_type); + jdomain, item2_type); root->eq_classes = lappend(root->eq_classes, ec); @@ -566,11 +584,13 @@ canonicalize_ec_expression(Expr *expr, Oid req_type, Oid req_collation) } /* - * add_eq_member - build a new EquivalenceMember and add it to an EC + * make_eq_member + * Build a new EquivalenceMember without adding it to an EC. If 'parent' + * is NULL, the result will be a parent member, otherwise a child member. */ static EquivalenceMember * -add_eq_member(EquivalenceClass *ec, Expr *expr, Relids relids, - JoinDomain *jdomain, EquivalenceMember *parent, Oid datatype) +make_eq_member(EquivalenceClass *ec, Expr *expr, Relids relids, + JoinDomain *jdomain, EquivalenceMember *parent, Oid datatype) { EquivalenceMember *em = makeNode(EquivalenceMember); @@ -597,11 +617,84 @@ add_eq_member(EquivalenceClass *ec, Expr *expr, Relids relids, ec->ec_has_const = true; /* it can't affect ec_relids */ } - else if (!parent) /* child members don't add to ec_relids */ + + return em; +} + +/* + * add_eq_member - build a new non-child EquivalenceMember and add it to 'ec'. + */ +static EquivalenceMember * +add_eq_member(EquivalenceClass *ec, Expr *expr, Relids relids, + JoinDomain *jdomain, Oid datatype) +{ + EquivalenceMember *em = make_eq_member(ec, expr, relids, jdomain, + NULL, datatype); + + /* add to the members list */ + ec->ec_members = lappend(ec->ec_members, em); + + /* record the relids for parent members */ + ec->ec_relids = bms_add_members(ec->ec_relids, relids); + + return em; +} + +/* + * add_child_eq_member + * Create an em_is_child=true EquivalenceMember and add it to 'ec'. + * + * 'root' the PlannerInfo that 'ec' belongs to. + * 'ec' the EquivalenceClass to add the child member to. + * 'ec_index' the index of 'ec' within root->eq_classes, or -1 if maintaining + * the RelOptInfo.eclass_indexes isn't needed. + * 'expr' the em_expr for the new member. + * 'relids' the 'em_relids' for the new member. + * 'jdomain' the 'em_jdomain' for the new member. + * 'parent_em' the parent member of the child to create. + * 'datatype' the em_datatype of the new member. + * 'child_relids' defines which elements of ec_childmembers to add this member + * to. + */ +static EquivalenceMember * +add_child_eq_member(PlannerInfo *root, EquivalenceClass *ec, int ec_index, + Expr *expr, Relids relids, JoinDomain *jdomain, + EquivalenceMember *parent_em, Oid datatype, + Relids child_relids) +{ + EquivalenceMember *em; + int relid; + + Assert(parent_em != NULL); + + /* + * Allocate member to store children. An array of Lists indexed by relid. + */ + if (ec->ec_childmembers == NULL) { - ec->ec_relids = bms_add_members(ec->ec_relids, relids); + ec->ec_childmembers = (List **) palloc0(root->simple_rel_array_size * + sizeof(List *)); + ec->ec_childmembers_size = root->simple_rel_array_size; + } + + em = make_eq_member(ec, expr, relids, jdomain, parent_em, datatype); + + /* Record this member in the ec_childmembers Lists for each relid */ + relid = -1; + while ((relid = bms_next_member(child_relids, relid)) >= 0) + { + + ec->ec_childmembers[relid] = lappend(ec->ec_childmembers[relid], em); + + /* Record this EC index for the child rel */ + if (ec_index >= 0) + { + RelOptInfo *child_rel = root->simple_rel_array[relid]; + + child_rel->eclass_indexes = + bms_add_member(child_rel->eclass_indexes, ec_index); + } } - ec->ec_members = lappend(ec->ec_members, em); return em; } @@ -672,7 +765,8 @@ get_eclass_for_sort_expr(PlannerInfo *root, foreach(lc1, root->eq_classes) { EquivalenceClass *cur_ec = (EquivalenceClass *) lfirst(lc1); - ListCell *lc2; + EquivalenceMemberIterator it; + EquivalenceMember *cur_em; /* * Never match to a volatile EC, except when we are looking at another @@ -687,10 +781,9 @@ get_eclass_for_sort_expr(PlannerInfo *root, if (!equal(opfamilies, cur_ec->ec_opfamilies)) continue; - foreach(lc2, cur_ec->ec_members) + setup_eclass_member_iterator(&it, cur_ec, rel); + while ((cur_em = eclass_member_iterator_next(&it)) != NULL) { - EquivalenceMember *cur_em = (EquivalenceMember *) lfirst(lc2); - /* * Ignore child members unless they match the request. */ @@ -725,7 +818,9 @@ get_eclass_for_sort_expr(PlannerInfo *root, newec = makeNode(EquivalenceClass); newec->ec_opfamilies = list_copy(opfamilies); newec->ec_collation = collation; + newec->ec_childmembers_size = 0; newec->ec_members = NIL; + newec->ec_childmembers = NULL; newec->ec_sources = NIL; newec->ec_derives_list = NIL; newec->ec_derives_hash = NULL; @@ -747,7 +842,7 @@ get_eclass_for_sort_expr(PlannerInfo *root, expr_relids = pull_varnos(root, (Node *) expr); newem = add_eq_member(newec, copyObject(expr), expr_relids, - jdomain, NULL, opcintype); + jdomain, opcintype); /* * add_eq_member doesn't check for volatile functions, set-returning @@ -821,15 +916,16 @@ find_ec_member_matching_expr(EquivalenceClass *ec, Expr *expr, Relids relids) { - ListCell *lc; + EquivalenceMemberIterator it; + EquivalenceMember *em; /* We ignore binary-compatible relabeling on both ends */ while (expr && IsA(expr, RelabelType)) expr = ((RelabelType *) expr)->arg; - foreach(lc, ec->ec_members) + setup_eclass_member_iterator(&it, ec, relids); + while ((em = eclass_member_iterator_next(&it)) != NULL) { - EquivalenceMember *em = (EquivalenceMember *) lfirst(lc); Expr *emexpr; /* @@ -898,7 +994,8 @@ find_computable_ec_member(PlannerInfo *root, bool require_parallel_safe) { List *exprvars; - ListCell *lc; + EquivalenceMemberIterator it; + EquivalenceMember *em; /* * Pull out the Vars and quasi-Vars present in "exprs". In the typical @@ -912,9 +1009,9 @@ find_computable_ec_member(PlannerInfo *root, PVC_INCLUDE_PLACEHOLDERS | PVC_INCLUDE_CONVERTROWTYPES); - foreach(lc, ec->ec_members) + setup_eclass_member_iterator(&it, ec, relids); + while ((em = eclass_member_iterator_next(&it)) != NULL) { - EquivalenceMember *em = (EquivalenceMember *) lfirst(lc); List *emvars; ListCell *lc2; @@ -1193,6 +1290,9 @@ generate_base_implied_equalities_const(PlannerInfo *root, return; } + /* We don't expect any children yet */ + Assert(ec->ec_childmembers == NULL); + /* * Find the constant member to use. We prefer an actual constant to * pseudo-constants (such as Params), because the constraint exclusion @@ -1219,7 +1319,8 @@ generate_base_implied_equalities_const(PlannerInfo *root, Oid eq_op; RestrictInfo *rinfo; - Assert(!cur_em->em_is_child); /* no children yet */ + Assert(!cur_em->em_is_child); /* Child members should not exist in + * ec_members */ if (cur_em == const_em) continue; eq_op = select_equality_operator(ec, @@ -1283,12 +1384,16 @@ generate_base_implied_equalities_no_const(PlannerInfo *root, prev_ems = (EquivalenceMember **) palloc0(root->simple_rel_array_size * sizeof(EquivalenceMember *)); + /* We don't expect any children yet */ + Assert(ec->ec_childmembers == NULL); + foreach(lc, ec->ec_members) { EquivalenceMember *cur_em = (EquivalenceMember *) lfirst(lc); int relid; - Assert(!cur_em->em_is_child); /* no children yet */ + Assert(!cur_em->em_is_child); /* Child members should not exist in + * ec_members */ if (!bms_get_singleton_member(cur_em->em_relids, &relid)) continue; Assert(relid < root->simple_rel_array_size); @@ -1621,7 +1726,8 @@ generate_join_implied_equalities_normal(PlannerInfo *root, List *new_members = NIL; List *outer_members = NIL; List *inner_members = NIL; - ListCell *lc1; + EquivalenceMemberIterator it; + EquivalenceMember *cur_em; /* * First, scan the EC to identify member values that are computable at the @@ -1632,10 +1738,9 @@ generate_join_implied_equalities_normal(PlannerInfo *root, * as well as to at least one input member, plus enforce at least one * outer-rel member equal to at least one inner-rel member. */ - foreach(lc1, ec->ec_members) + setup_eclass_member_iterator(&it, ec, join_relids); + while ((cur_em = eclass_member_iterator_next(&it)) != NULL) { - EquivalenceMember *cur_em = (EquivalenceMember *) lfirst(lc1); - /* * We don't need to check explicitly for child EC members. This test * against join_relids will cause them to be ignored except when @@ -1668,6 +1773,7 @@ generate_join_implied_equalities_normal(PlannerInfo *root, Oid best_eq_op = InvalidOid; int best_score = -1; RestrictInfo *rinfo; + ListCell *lc1; foreach(lc1, outer_members) { @@ -1742,6 +1848,7 @@ generate_join_implied_equalities_normal(PlannerInfo *root, List *old_members = list_concat(outer_members, inner_members); EquivalenceMember *prev_em = NULL; RestrictInfo *rinfo; + ListCell *lc1; /* For now, arbitrarily take the first old_member as the one to use */ if (old_members) @@ -1749,7 +1856,7 @@ generate_join_implied_equalities_normal(PlannerInfo *root, foreach(lc1, new_members) { - EquivalenceMember *cur_em = (EquivalenceMember *) lfirst(lc1); + cur_em = (EquivalenceMember *) lfirst(lc1); if (prev_em != NULL) { @@ -2189,6 +2296,9 @@ reconsider_outer_join_clause(PlannerInfo *root, OuterJoinClauseInfo *ojcinfo, bool match; ListCell *lc2; + /* We don't expect any children yet */ + Assert(cur_ec->ec_childmembers == NULL); + /* Ignore EC unless it contains pseudoconstants */ if (!cur_ec->ec_has_const) continue; @@ -2206,7 +2316,8 @@ reconsider_outer_join_clause(PlannerInfo *root, OuterJoinClauseInfo *ojcinfo, { EquivalenceMember *cur_em = (EquivalenceMember *) lfirst(lc2); - Assert(!cur_em->em_is_child); /* no children yet */ + Assert(!cur_em->em_is_child); /* Child members should not exist + * in ec_members */ if (equal(outervar, cur_em->em_expr)) { match = true; @@ -2304,6 +2415,9 @@ reconsider_full_join_clause(PlannerInfo *root, OuterJoinClauseInfo *ojcinfo) ListCell *lc2; int coal_idx = -1; + /* We don't expect any children yet */ + Assert(cur_ec->ec_childmembers == NULL); + /* Ignore EC unless it contains pseudoconstants */ if (!cur_ec->ec_has_const) continue; @@ -2333,7 +2447,8 @@ reconsider_full_join_clause(PlannerInfo *root, OuterJoinClauseInfo *ojcinfo) foreach(lc2, cur_ec->ec_members) { coal_em = (EquivalenceMember *) lfirst(lc2); - Assert(!coal_em->em_is_child); /* no children yet */ + Assert(!coal_em->em_is_child); /* Child members should not exist + * in ec_members */ if (IsA(coal_em->em_expr, CoalesceExpr)) { CoalesceExpr *cexpr = (CoalesceExpr *) coal_em->em_expr; @@ -2462,6 +2577,9 @@ rebuild_eclass_attr_needed(PlannerInfo *root) { EquivalenceClass *ec = (EquivalenceClass *) lfirst(lc); + /* We don't expect any children yet */ + Assert(ec->ec_childmembers == NULL); + /* Need do anything only for a multi-member, no-const EC. */ if (list_length(ec->ec_members) > 1 && !ec->ec_has_const) { @@ -2547,12 +2665,13 @@ exprs_known_equal(PlannerInfo *root, Node *item1, Node *item2, Oid opfamily) !list_member_oid(ec->ec_opfamilies, opfamily)) continue; + /* Ignore children here */ foreach(lc2, ec->ec_members) { EquivalenceMember *em = (EquivalenceMember *) lfirst(lc2); - if (em->em_is_child) - continue; /* ignore children here */ + Assert(!em->em_is_child); /* Child members should not exist in + * ec_members */ if (equal(item1, em->em_expr)) item1member = true; else if (equal(item2, em->em_expr)) @@ -2616,15 +2735,18 @@ match_eclasses_to_foreign_key_col(PlannerInfo *root, /* Never match to a volatile EC */ if (ec->ec_has_volatile) continue; - /* It's okay to consider "broken" ECs here, see exprs_known_equal */ + /* + * It's okay to consider "broken" ECs here, see exprs_known_equal. + * Ignore children here. + */ foreach(lc2, ec->ec_members) { EquivalenceMember *em = (EquivalenceMember *) lfirst(lc2); Var *var; - if (em->em_is_child) - continue; /* ignore children here */ + /* Child members should not exist in ec_members */ + Assert(!em->em_is_child); /* EM must be a Var, possibly with RelabelType */ var = (Var *) em->em_expr; @@ -2710,6 +2832,7 @@ add_child_rel_equivalences(PlannerInfo *root, Relids top_parent_relids = child_rel->top_parent_relids; Relids child_relids = child_rel->relids; int i; + ListCell *lc; /* * EC merging should be complete already, so we can use the parent rel's @@ -2722,7 +2845,6 @@ add_child_rel_equivalences(PlannerInfo *root, while ((i = bms_next_member(parent_rel->eclass_indexes, i)) >= 0) { EquivalenceClass *cur_ec = (EquivalenceClass *) list_nth(root->eq_classes, i); - int num_members; /* * If this EC contains a volatile expression, then generating child @@ -2735,29 +2857,15 @@ add_child_rel_equivalences(PlannerInfo *root, /* Sanity check eclass_indexes only contain ECs for parent_rel */ Assert(bms_is_subset(top_parent_relids, cur_ec->ec_relids)); - /* - * We don't use foreach() here because there's no point in scanning - * newly-added child members, so we can stop after the last - * pre-existing EC member. - */ - num_members = list_length(cur_ec->ec_members); - for (int pos = 0; pos < num_members; pos++) + foreach(lc, cur_ec->ec_members) { - EquivalenceMember *cur_em = (EquivalenceMember *) list_nth(cur_ec->ec_members, pos); + EquivalenceMember *cur_em = lfirst_node(EquivalenceMember, lc); if (cur_em->em_is_const) continue; /* ignore consts here */ - /* - * We consider only original EC members here, not - * already-transformed child members. Otherwise, if some original - * member expression references more than one appendrel, we'd get - * an O(N^2) explosion of useless derived expressions for - * combinations of children. (But add_child_join_rel_equivalences - * may add targeted combinations for partitionwise-join purposes.) - */ - if (cur_em->em_is_child) - continue; /* ignore children here */ + /* Child members should not exist in ec_members */ + Assert(!cur_em->em_is_child); /* * Consider only members that reference and can be computed at @@ -2802,12 +2910,15 @@ add_child_rel_equivalences(PlannerInfo *root, top_parent_relids); new_relids = bms_add_members(new_relids, child_relids); - (void) add_eq_member(cur_ec, child_expr, new_relids, - cur_em->em_jdomain, - cur_em, cur_em->em_datatype); - - /* Record this EC index for the child rel */ - child_rel->eclass_indexes = bms_add_member(child_rel->eclass_indexes, i); + add_child_eq_member(root, + cur_ec, + i, + child_expr, + new_relids, + cur_em->em_jdomain, + cur_em, + cur_em->em_datatype, + child_rel->relids); } } } @@ -2854,7 +2965,7 @@ add_child_join_rel_equivalences(PlannerInfo *root, while ((i = bms_next_member(matching_ecs, i)) >= 0) { EquivalenceClass *cur_ec = (EquivalenceClass *) list_nth(root->eq_classes, i); - int num_members; + ListCell *lc; /* * If this EC contains a volatile expression, then generating child @@ -2867,25 +2978,15 @@ add_child_join_rel_equivalences(PlannerInfo *root, /* Sanity check on get_eclass_indexes_for_relids result */ Assert(bms_overlap(top_parent_relids, cur_ec->ec_relids)); - /* - * We don't use foreach() here because there's no point in scanning - * newly-added child members, so we can stop after the last - * pre-existing EC member. - */ - num_members = list_length(cur_ec->ec_members); - for (int pos = 0; pos < num_members; pos++) + foreach(lc, cur_ec->ec_members) { - EquivalenceMember *cur_em = (EquivalenceMember *) list_nth(cur_ec->ec_members, pos); + EquivalenceMember *cur_em = lfirst_node(EquivalenceMember, lc); if (cur_em->em_is_const) continue; /* ignore consts here */ - /* - * We consider only original EC members here, not - * already-transformed child members. - */ - if (cur_em->em_is_child) - continue; /* ignore children here */ + /* Child members should not exist in ec_members */ + Assert(!cur_em->em_is_child); /* * We may ignore expressions that reference a single baserel, @@ -2930,9 +3031,15 @@ add_child_join_rel_equivalences(PlannerInfo *root, top_parent_relids); new_relids = bms_add_members(new_relids, child_relids); - (void) add_eq_member(cur_ec, child_expr, new_relids, - cur_em->em_jdomain, - cur_em, cur_em->em_datatype); + add_child_eq_member(root, + cur_ec, + -1, + child_expr, + new_relids, + cur_em->em_jdomain, + cur_em, + cur_em->em_datatype, + child_joinrel->relids); } } } @@ -2979,14 +3086,18 @@ add_setop_child_rel_equivalences(PlannerInfo *root, RelOptInfo *child_rel, * We can safely pass the parent member as the first member in the * ec_members list as this is added first in generate_union_paths, * likewise, the JoinDomain can be that of the initial member of the - * Pathkey's EquivalenceClass. + * Pathkey's EquivalenceClass. We pass -1 for ec_index since we + * maintain the eclass_indexes for the child_rel after the loop. */ - add_eq_member(pk->pk_eclass, - tle->expr, - child_rel->relids, - parent_em->em_jdomain, - parent_em, - exprType((Node *) tle->expr)); + add_child_eq_member(root, + pk->pk_eclass, + -1, + tle->expr, + child_rel->relids, + parent_em->em_jdomain, + parent_em, + exprType((Node *) tle->expr), + child_rel->relids); lc2 = lnext(setop_pathkeys, lc2); } @@ -3001,6 +3112,83 @@ add_setop_child_rel_equivalences(PlannerInfo *root, RelOptInfo *child_rel, list_length(root->eq_classes) - 1); } +/* + * setup_eclass_member_iterator + * Setup an EquivalenceMemberIterator 'it' to iterate over all parent + * EquivalenceMembers and child members belonging to the given 'ec'. + * + * This iterator returns: + * - All parent members stored directly in ec_members for 'ec', and; + * - Any child member added to the given ec by add_child_eq_member() where + * the child_relids specified in the add_child_eq_member() overlap with + * the child_relids in the setup_eclass_member_iterator() call. + * + * Note: + * - The given 'child_relids' must remain allocated and not be changed for + * the lifetime of the iterator. + * + * Parameters: + * it - A pointer to the iterator to set up. + * ec - The EquivalenceClass from which to iterate members. + * child_relids - The relids to return child members for. + */ +void +setup_eclass_member_iterator(EquivalenceMemberIterator *it, + EquivalenceClass *ec, Relids child_relids) +{ + it->ec = ec; + /* no need to set this if the class has no child members */ + it->child_relids = ec->ec_childmembers ? child_relids : NULL; + it->current_relid = -1; + it->current_list = ec->ec_members; + it->current_cell = list_head(it->current_list); +} + +/* + * eclass_member_iterator_next + * Get a next EquivalenceMember from an EquivalenceMemberIterator 'it' + * that was setup by setup_eclass_member_iterator(). NULL is + * returned if there are no members left, in which case callers must not + * call eclass_member_iterator_next() again for the given iterator. + */ +EquivalenceMember * +eclass_member_iterator_next(EquivalenceMemberIterator *it) +{ + EquivalenceMember *em = NULL; + + while (it->current_list != NULL) + { +nextcell: + while (it->current_cell != NULL) + { + em = lfirst_node(EquivalenceMember, it->current_cell); + it->current_cell = lnext(it->current_list, it->current_cell); + goto end; + } + + /* Search for the next list to return members from */ + while ((it->current_relid = bms_next_member(it->child_relids, it->current_relid)) > 0) + { + it->current_list = it->ec->ec_childmembers[it->current_relid]; + + /* + * If there are members in this list, use it, this will exclude + * RELOPT_BASERELs as ec_childmembers[] are not populated for + * those. + */ + if (it->current_list != NIL) + { + /* point current_cell to the head of this list */ + it->current_cell = list_head(it->current_list); + goto nextcell; + } + } + goto end; + } + +end: + return em; +} /* * generate_implied_equalities_for_column @@ -3053,6 +3241,7 @@ generate_implied_equalities_for_column(PlannerInfo *root, while ((i = bms_next_member(rel->eclass_indexes, i)) >= 0) { EquivalenceClass *cur_ec = (EquivalenceClass *) list_nth(root->eq_classes, i); + EquivalenceMemberIterator it; EquivalenceMember *cur_em; ListCell *lc2; @@ -3076,14 +3265,12 @@ generate_implied_equalities_for_column(PlannerInfo *root, * corner cases, so for now we live with just reporting the first * match. See also get_eclass_for_sort_expr.) */ - cur_em = NULL; - foreach(lc2, cur_ec->ec_members) + setup_eclass_member_iterator(&it, cur_ec, rel->relids); + while ((cur_em = eclass_member_iterator_next(&it)) != NULL) { - cur_em = (EquivalenceMember *) lfirst(lc2); if (bms_equal(cur_em->em_relids, rel->relids) && callback(root, rel, cur_ec, cur_em, callback_arg)) break; - cur_em = NULL; } if (!cur_em) @@ -3091,7 +3278,7 @@ generate_implied_equalities_for_column(PlannerInfo *root, /* * Found our match. Scan the other EC members and attempt to generate - * joinclauses. + * joinclauses. Ignore children here. */ foreach(lc2, cur_ec->ec_members) { @@ -3099,8 +3286,8 @@ generate_implied_equalities_for_column(PlannerInfo *root, Oid eq_op; RestrictInfo *rinfo; - if (other_em->em_is_child) - continue; /* ignore children here */ + /* Child members should not exist in ec_members */ + Assert(!other_em->em_is_child); /* Make sure it'll be a join to a different rel */ if (other_em == cur_em || @@ -3313,13 +3500,15 @@ eclass_useful_for_merging(PlannerInfo *root, if (bms_is_subset(eclass->ec_relids, relids)) return false; - /* To join, we need a member not in the given rel */ + /* + * To join, we need a member not in the given rel. Ignore children here. + */ foreach(lc, eclass->ec_members) { EquivalenceMember *cur_em = (EquivalenceMember *) lfirst(lc); - if (cur_em->em_is_child) - continue; /* ignore children here */ + /* Child members should not exist in ec_members */ + Assert(!cur_em->em_is_child); if (!bms_overlap(cur_em->em_relids, relids)) return true; diff --git a/src/backend/optimizer/path/indxpath.c b/src/backend/optimizer/path/indxpath.c index 4cabb358abc..601354ea3e0 100644 --- a/src/backend/optimizer/path/indxpath.c +++ b/src/backend/optimizer/path/indxpath.c @@ -3755,7 +3755,8 @@ match_pathkeys_to_index(IndexOptInfo *index, List *pathkeys, { PathKey *pathkey = (PathKey *) lfirst(lc1); bool found = false; - ListCell *lc2; + EquivalenceMemberIterator it; + EquivalenceMember *member; /* Pathkey must request default sort order for the target opfamily */ @@ -3774,9 +3775,10 @@ match_pathkeys_to_index(IndexOptInfo *index, List *pathkeys, * be considered to match more than one pathkey list, which is OK * here. See also get_eclass_for_sort_expr.) */ - foreach(lc2, pathkey->pk_eclass->ec_members) + setup_eclass_member_iterator(&it, pathkey->pk_eclass, + index->rel->relids); + while ((member = eclass_member_iterator_next(&it)) != NULL) { - EquivalenceMember *member = (EquivalenceMember *) lfirst(lc2); int indexcol; /* No possibility of match if it references other relations */ diff --git a/src/backend/optimizer/path/pathkeys.c b/src/backend/optimizer/path/pathkeys.c index 6fac08cb0d9..4e8923e383e 100644 --- a/src/backend/optimizer/path/pathkeys.c +++ b/src/backend/optimizer/path/pathkeys.c @@ -1143,6 +1143,7 @@ convert_subquery_pathkeys(PlannerInfo *root, RelOptInfo *rel, int best_score = -1; ListCell *j; + /* Ignore children here */ foreach(j, sub_eclass->ec_members) { EquivalenceMember *sub_member = (EquivalenceMember *) lfirst(j); @@ -1151,8 +1152,8 @@ convert_subquery_pathkeys(PlannerInfo *root, RelOptInfo *rel, Oid sub_expr_coll = sub_eclass->ec_collation; ListCell *k; - if (sub_member->em_is_child) - continue; /* ignore children here */ + /* Child members should not exist in ec_members */ + Assert(!sub_member->em_is_child); foreach(k, subquery_tlist) { @@ -1709,8 +1710,11 @@ select_outer_pathkeys_for_merge(PlannerInfo *root, { EquivalenceMember *em = (EquivalenceMember *) lfirst(lc2); + /* Child members should not exist in ec_members */ + Assert(!em->em_is_child); + /* Potential future join partner? */ - if (!em->em_is_const && !em->em_is_child && + if (!em->em_is_const && !bms_overlap(em->em_relids, joinrel->relids)) score++; } diff --git a/src/backend/optimizer/plan/analyzejoins.c b/src/backend/optimizer/plan/analyzejoins.c index ae20691ca91..c9f3b7f08ef 100644 --- a/src/backend/optimizer/plan/analyzejoins.c +++ b/src/backend/optimizer/plan/analyzejoins.c @@ -710,6 +710,13 @@ remove_rel_from_eclass(EquivalenceClass *ec, SpecialJoinInfo *sjinfo, ec->ec_relids = adjust_relid_set(ec->ec_relids, sjinfo->ojrelid, subst); + /* + * We don't expect any EC child members to exist at this point. Ensure + * that's the case, otherwise we might be getting asked to do something + * this function hasn't been coded for. + */ + Assert(ec->ec_childmembers == NULL); + /* * Fix up the member expressions. Any non-const member that ends with * empty em_relids must be a Var or PHV of the removed relation. We don't @@ -1509,6 +1516,13 @@ update_eclasses(EquivalenceClass *ec, int from, int to) List *new_members = NIL; List *new_sources = NIL; + /* + * We don't expect any EC child members to exist at this point. Ensure + * that's the case, otherwise we might be getting asked to do something + * this function hasn't been coded for. + */ + Assert(ec->ec_childmembers == NULL); + foreach_node(EquivalenceMember, em, ec->ec_members) { bool is_redundant = false; diff --git a/src/include/nodes/pathnodes.h b/src/include/nodes/pathnodes.h index 4c466f76778..59ddafca1cf 100644 --- a/src/include/nodes/pathnodes.h +++ b/src/include/nodes/pathnodes.h @@ -1414,6 +1414,22 @@ typedef struct JoinDomain * In contrast, ec_sources holds equality clauses that appear directly in the * query. These are typically few and do not require a hash table for lookup. * + * 'ec_members' is a List of all EquivalenceMembers belonging to + * RELOPT_BASERELs. EquivalenceMembers for any RELOPT_OTHER_MEMBER_REL and + * RELOPT_OTHER_JOINREL relations are stored in the 'ec_childmembers' array in + * the index corresponding to the relid. 'ec_childmembers' may be NULL if the + * class has no child EquivalenceMembers. + * + * For code wishing to look at EquivalenceMembers, if only parent-level + * members are needed, then a simple foreach loop over ec_members is + * sufficient. When child members are also required, it is best to use the + * functionality provided by EquivalenceMemberIterator. The reason for this + * is because large numbers of child EquivalenceMembers can exist in queries + * to partitioned tables with many partitions. The functionality provided by + * EquivalenceMemberIterator allows efficient access to EquivalenceMembers + * which belong to specific child relids. See the header comments for + * EquivalenceMemberIterator below for further details. + * * NB: if ec_merged isn't NULL, this class has been merged into another, and * should be ignored in favor of using the pointed-to class. * @@ -1431,7 +1447,10 @@ typedef struct EquivalenceClass List *ec_opfamilies; /* btree operator family OIDs */ Oid ec_collation; /* collation, if datatypes are collatable */ + int ec_childmembers_size; /* # elements in ec_childmembers */ List *ec_members; /* list of EquivalenceMembers */ + List **ec_childmembers; /* array of Lists of child + * EquivalenceMembers */ List *ec_sources; /* list of generating RestrictInfos */ List *ec_derives_list; /* list of derived RestrictInfos */ struct derives_hash *ec_derives_hash; /* optional hash table for fast @@ -1465,12 +1484,17 @@ typedef struct EquivalenceClass * child when necessary to build a MergeAppend path for the whole appendrel * tree. An em_is_child member has no impact on the properties of the EC as a * whole; in particular the EC's ec_relids field does NOT include the child - * relation. An em_is_child member should never be marked em_is_const nor - * cause ec_has_const or ec_has_volatile to be set, either. Thus, em_is_child + * relation. em_is_child members aren't stored in the ec_members List of the + * EC and instead they're stored and indexed by the relids of the child + * relation(s) they represent equivalence for in ec_childmembers. An + * em_is_child member should never be marked em_is_const nor cause + * ec_has_const or ec_has_volatile to be set, either. Thus, em_is_child * members are not really full-fledged members of the EC, but just reflections * or doppelgangers of real members. Most operations on EquivalenceClasses - * should ignore em_is_child members, and those that don't should test - * em_relids to make sure they only consider relevant members. + * should ignore em_is_child members by only inspecting members in the + * ec_members list. Callers that require inspecting child members should do + * so using an EquivalenceMemberIterator and should test em_relids to make + * sure they only consider relevant members. * * em_datatype is usually the same as exprType(em_expr), but can be * different when dealing with a binary-compatible opfamily; in particular @@ -1493,6 +1517,70 @@ typedef struct EquivalenceMember struct EquivalenceMember *em_parent pg_node_attr(read_write_ignore); } EquivalenceMember; +/* + * EquivalenceMemberIterator + * + * EquivalenceMemberIterator allows efficient access to sets of + * EquivalenceMembers for callers which require access to child members. + * Because partitioning workloads can result in large numbers of child + * members, the child members are not stored in the EquivalenceClass's + * ec_members List. Instead, these are stored in the EquivalenceClass's + * ec_childmembers array of Lists. The functionality provided by + * EquivalenceMemberIterator aims to provide efficient access to parent + * members and child members belonging to specific child relids. + * + * Currently, there is only one way to initialize and iterate over an + * EquivalenceMemberIterator and that is via the setup_eclass_member_iterator + * and eclass_member_iterator_next functions. The iterator object is + * generally a local variable which is passed by address to + * setup_eclass_member_iterator. The calling function defines which + * EquivalenceClass the iterator should be looking at and which child + * relids to also include the members for. child_relids can be passed as NULL + * but the caller may as well just perform a foreach loop over ec_members as + * only parent-level members will be returned in that case. + * + * When calling the next function on an EquivalenceMemberIterator, all + * parent-level EquivalenceMembers are returned first, followed by any + * child members for the relids specified by the child_relids parameter as + * specified when calling setup_eclass_member_iterator. The child members + * returned are members which have any of the relids mentioned in + * child_relids. That's not to be confused with returning members which + * contain *all* of the child relids specified when calling + * setup_eclass_member_iterator. It is up to the calling function to ensure + * that the returned member matches what is required for the purpose. + * + * It is also important to note that when dealing with child + * EquivalenceMembers for RELOPT_OTHER_JOINRELs that it's possible for the + * same EquivalenceMembers to be returned more than once by the next function. + * This is currently not seen to be a problem, but some callers may want to be + * aware of it. + * + * The most common way to use this iterator is as follows: + * ----- + * EquivalenceMemberIterator it; + * EquivalenceMember *em; + * + * setup_eclass_member_iterator(&it, ec, child_relids); + * while ((em = eclass_member_iterator_next(&it)) != NULL) + * { + * ... + * } + * ----- + * It is not valid to call eclass_member_iterator_next() after it has returned + * NULL for any given EquivalenceMemberIterator. + */ +typedef struct +{ + EquivalenceClass *ec; /* The EquivalenceClass to iterate over */ + int current_relid; /* Current relid position within 'relids'. -1 + * when still looping over ec_members and -2 + * at the end of iteration */ + Relids child_relids; /* Relids of child relations of interest. + * Non-child rels are ignored */ + ListCell *current_cell; /* Next cell to return within current_list */ + List *current_list; /* Current list of members being returned */ +} EquivalenceMemberIterator; + /* * PathKeys * diff --git a/src/include/optimizer/paths.h b/src/include/optimizer/paths.h index b1a76816442..a48c9721797 100644 --- a/src/include/optimizer/paths.h +++ b/src/include/optimizer/paths.h @@ -183,6 +183,10 @@ extern void add_setop_child_rel_equivalences(PlannerInfo *root, RelOptInfo *child_rel, List *child_tlist, List *setop_pathkeys); +extern void setup_eclass_member_iterator(EquivalenceMemberIterator *it, + EquivalenceClass *ec, + Relids child_relids); +extern EquivalenceMember *eclass_member_iterator_next(EquivalenceMemberIterator *it); extern List *generate_implied_equalities_for_column(PlannerInfo *root, RelOptInfo *rel, ec_matches_callback_type callback, diff --git a/src/tools/pgindent/typedefs.list b/src/tools/pgindent/typedefs.list index c3f05796a7c..1513b247d9d 100644 --- a/src/tools/pgindent/typedefs.list +++ b/src/tools/pgindent/typedefs.list @@ -711,6 +711,7 @@ EphemeralNamedRelationMetadata EphemeralNamedRelationMetadataData EquivalenceClass EquivalenceMember +EquivalenceMemberIterator ErrorContextCallback ErrorData ErrorSaveContext