diff options
Diffstat (limited to 'src/backend/optimizer/path/equivclass.c')
| -rw-r--r-- | src/backend/optimizer/path/equivclass.c | 168 |
1 files changed, 45 insertions, 123 deletions
diff --git a/src/backend/optimizer/path/equivclass.c b/src/backend/optimizer/path/equivclass.c index 490953f2ff5..007229d26cc 100644 --- a/src/backend/optimizer/path/equivclass.c +++ b/src/backend/optimizer/path/equivclass.c @@ -34,7 +34,7 @@ static EquivalenceMember *add_eq_member(EquivalenceClass *ec, - Expr *expr, Relids relids, Relids nullable_relids, + Expr *expr, Relids relids, EquivalenceMember *parent, Oid datatype); static bool is_exprlist_member(Expr *node, List *exprs); @@ -131,9 +131,7 @@ process_equivalence(PlannerInfo *root, Expr *item1; Expr *item2; Relids item1_relids, - item2_relids, - item1_nullable_relids, - item2_nullable_relids; + item2_relids; List *opfamilies; EquivalenceClass *ec1, *ec2; @@ -202,12 +200,10 @@ process_equivalence(PlannerInfo *root, make_restrictinfo(root, (Expr *) ntest, restrictinfo->is_pushed_down, - restrictinfo->outerjoin_delayed, restrictinfo->pseudoconstant, restrictinfo->security_level, NULL, - restrictinfo->outer_relids, - restrictinfo->nullable_relids); + restrictinfo->outer_relids); } return false; } @@ -225,12 +221,6 @@ process_equivalence(PlannerInfo *root, return false; /* RHS is non-strict but not constant */ } - /* Calculate nullable-relid sets for each side of the clause */ - item1_nullable_relids = bms_intersect(item1_relids, - restrictinfo->nullable_relids); - item2_nullable_relids = bms_intersect(item2_relids, - restrictinfo->nullable_relids); - /* * We use the declared input types of the operator, not exprType() of the * inputs, as the nominal datatypes for opfamily lookup. This presumes @@ -400,7 +390,7 @@ process_equivalence(PlannerInfo *root, else if (ec1) { /* Case 3: add item2 to ec1 */ - em2 = add_eq_member(ec1, item2, item2_relids, item2_nullable_relids, + em2 = add_eq_member(ec1, item2, item2_relids, NULL, item2_type); ec1->ec_sources = lappend(ec1->ec_sources, restrictinfo); ec1->ec_below_outer_join |= below_outer_join; @@ -418,7 +408,7 @@ process_equivalence(PlannerInfo *root, else if (ec2) { /* Case 3: add item1 to ec2 */ - em1 = add_eq_member(ec2, item1, item1_relids, item1_nullable_relids, + em1 = add_eq_member(ec2, item1, item1_relids, NULL, item1_type); ec2->ec_sources = lappend(ec2->ec_sources, restrictinfo); ec2->ec_below_outer_join |= below_outer_join; @@ -452,9 +442,9 @@ process_equivalence(PlannerInfo *root, ec->ec_min_security = restrictinfo->security_level; ec->ec_max_security = restrictinfo->security_level; ec->ec_merged = NULL; - em1 = add_eq_member(ec, item1, item1_relids, item1_nullable_relids, + em1 = add_eq_member(ec, item1, item1_relids, NULL, item1_type); - em2 = add_eq_member(ec, item2, item2_relids, item2_nullable_relids, + em2 = add_eq_member(ec, item2, item2_relids, NULL, item2_type); root->eq_classes = lappend(root->eq_classes, ec); @@ -545,13 +535,12 @@ canonicalize_ec_expression(Expr *expr, Oid req_type, Oid req_collation) */ static EquivalenceMember * add_eq_member(EquivalenceClass *ec, Expr *expr, Relids relids, - Relids nullable_relids, EquivalenceMember *parent, Oid datatype) + EquivalenceMember *parent, Oid datatype) { EquivalenceMember *em = makeNode(EquivalenceMember); em->em_expr = expr; em->em_relids = relids; - em->em_nullable_relids = nullable_relids; em->em_is_const = false; em->em_is_child = (parent != NULL); em->em_datatype = datatype; @@ -588,13 +577,6 @@ add_eq_member(EquivalenceClass *ec, Expr *expr, Relids relids, * equivalence class it is a member of; if none, optionally build a new * single-member EquivalenceClass for it. * - * expr is the expression, and nullable_relids is the set of base relids - * that are potentially nullable below it. We actually only care about - * the set of such relids that are used in the expression; but for caller - * convenience, we perform that intersection step here. The caller need - * only be sure that nullable_relids doesn't omit any nullable rels that - * might appear in the expr. - * * sortref is the SortGroupRef of the originating SortGroupClause, if any, * or zero if not. (It should never be zero if the expression is volatile!) * @@ -623,7 +605,6 @@ add_eq_member(EquivalenceClass *ec, Expr *expr, Relids relids, EquivalenceClass * get_eclass_for_sort_expr(PlannerInfo *root, Expr *expr, - Relids nullable_relids, List *opfamilies, Oid opcintype, Oid collation, @@ -719,13 +700,12 @@ get_eclass_for_sort_expr(PlannerInfo *root, elog(ERROR, "volatile EquivalenceClass has no sortref"); /* - * Get the precise set of nullable relids appearing in the expression. + * Get the precise set of relids appearing in the expression. */ expr_relids = pull_varnos(root, (Node *) expr); - nullable_relids = bms_intersect(nullable_relids, expr_relids); newem = add_eq_member(newec, copyObject(expr), expr_relids, - nullable_relids, NULL, opcintype); + NULL, opcintype); /* * add_eq_member doesn't check for volatile functions, set-returning @@ -1163,11 +1143,8 @@ generate_base_implied_equalities_const(PlannerInfo *root, { RestrictInfo *restrictinfo = (RestrictInfo *) linitial(ec->ec_sources); - if (bms_membership(restrictinfo->required_relids) != BMS_MULTIPLE) - { - distribute_restrictinfo_to_rels(root, restrictinfo); - return; - } + distribute_restrictinfo_to_rels(root, restrictinfo); + return; } /* @@ -1211,8 +1188,6 @@ generate_base_implied_equalities_const(PlannerInfo *root, rinfo = process_implied_equality(root, eq_op, ec->ec_collation, cur_em->em_expr, const_em->em_expr, bms_copy(ec->ec_relids), - bms_union(cur_em->em_nullable_relids, - const_em->em_nullable_relids), ec->ec_min_security, ec->ec_below_outer_join, cur_em->em_is_const); @@ -1285,8 +1260,6 @@ generate_base_implied_equalities_no_const(PlannerInfo *root, rinfo = process_implied_equality(root, eq_op, ec->ec_collation, prev_em->em_expr, cur_em->em_expr, bms_copy(ec->ec_relids), - bms_union(prev_em->em_nullable_relids, - cur_em->em_nullable_relids), ec->ec_min_security, ec->ec_below_outer_join, false); @@ -1889,8 +1862,6 @@ create_join_clause(PlannerInfo *root, rightem->em_expr, bms_union(leftem->em_relids, rightem->em_relids), - bms_union(leftem->em_nullable_relids, - rightem->em_nullable_relids), ec->ec_min_security); /* If it's a child clause, copy the parent's rinfo_serial */ @@ -1979,23 +1950,11 @@ create_join_clause(PlannerInfo *root, * If we don't find any match for a set-aside outer join clause, we must * throw it back into the regular joinclause processing by passing it to * distribute_restrictinfo_to_rels(). If we do generate a derived clause, - * however, the outer-join clause is redundant. We still throw it back, - * because otherwise the join will be seen as a clauseless join and avoided - * during join order searching; but we mark it as redundant to keep from - * messing up the joinrel's size estimate. (This behavior means that the - * API for this routine is uselessly complex: we could have just put all - * the clauses into the regular processing initially. We keep it because - * someday we might want to do something else, such as inserting "dummy" - * joinclauses instead of real ones.) - * - * Outer join clauses that are marked outerjoin_delayed are special: this - * condition means that one or both VARs might go to null due to a lower - * outer join. We can still push a constant through the clause, but only - * if its operator is strict; and we *have to* throw the clause back into - * regular joinclause processing. By keeping the strict join clause, - * we ensure that any null-extended rows that are mistakenly generated due - * to suppressing rows not matching the constant will be rejected at the - * upper outer join. (This doesn't work for full-join clauses.) + * however, the outer-join clause is redundant. We must still put some + * clause into the regular processing, because otherwise the join will be + * seen as a clauseless join and avoided during join order searching. + * We handle this by generating a constant-TRUE clause that is marked with + * required_relids that make it a join between the correct relations. */ void reconsider_outer_join_clauses(PlannerInfo *root) @@ -2021,10 +1980,14 @@ reconsider_outer_join_clauses(PlannerInfo *root) /* remove it from the list */ root->left_join_clauses = foreach_delete_current(root->left_join_clauses, cell); - /* we throw it back anyway (see notes above) */ - /* but the thrown-back clause has no extra selectivity */ - rinfo->norm_selec = 2.0; - rinfo->outer_selec = 1.0; + /* throw back a dummy replacement clause (see notes above) */ + rinfo = make_restrictinfo(root, + (Expr *) makeBoolConst(true, false), + true, /* is_pushed_down */ + false, /* pseudoconstant */ + 0, /* security_level */ + rinfo->required_relids, + rinfo->outer_relids); distribute_restrictinfo_to_rels(root, rinfo); } } @@ -2042,10 +2005,14 @@ reconsider_outer_join_clauses(PlannerInfo *root) /* remove it from the list */ root->right_join_clauses = foreach_delete_current(root->right_join_clauses, cell); - /* we throw it back anyway (see notes above) */ - /* but the thrown-back clause has no extra selectivity */ - rinfo->norm_selec = 2.0; - rinfo->outer_selec = 1.0; + /* throw back a dummy replacement clause (see notes above) */ + rinfo = make_restrictinfo(root, + (Expr *) makeBoolConst(true, false), + true, /* is_pushed_down */ + false, /* pseudoconstant */ + 0, /* security_level */ + rinfo->required_relids, + rinfo->outer_relids); distribute_restrictinfo_to_rels(root, rinfo); } } @@ -2063,10 +2030,14 @@ reconsider_outer_join_clauses(PlannerInfo *root) /* remove it from the list */ root->full_join_clauses = foreach_delete_current(root->full_join_clauses, cell); - /* we throw it back anyway (see notes above) */ - /* but the thrown-back clause has no extra selectivity */ - rinfo->norm_selec = 2.0; - rinfo->outer_selec = 1.0; + /* throw back a dummy replacement clause (see notes above) */ + rinfo = make_restrictinfo(root, + (Expr *) makeBoolConst(true, false), + true, /* is_pushed_down */ + false, /* pseudoconstant */ + 0, /* security_level */ + rinfo->required_relids, + rinfo->outer_relids); distribute_restrictinfo_to_rels(root, rinfo); } } @@ -2110,18 +2081,13 @@ reconsider_outer_join_clause(PlannerInfo *root, OuterJoinClauseInfo *ojcinfo, left_type, right_type, inner_datatype; - Relids inner_relids, - inner_nullable_relids; + Relids inner_relids; ListCell *lc1; Assert(is_opclause(rinfo->clause)); opno = ((OpExpr *) rinfo->clause)->opno; collation = ((OpExpr *) rinfo->clause)->inputcollid; - /* If clause is outerjoin_delayed, operator must be strict */ - if (rinfo->outerjoin_delayed && !op_strict(opno)) - return false; - /* Extract needed info from the clause */ op_input_types(opno, &left_type, &right_type); if (outer_on_left) @@ -2138,8 +2104,6 @@ reconsider_outer_join_clause(PlannerInfo *root, OuterJoinClauseInfo *ojcinfo, inner_datatype = left_type; inner_relids = rinfo->left_relids; } - inner_nullable_relids = bms_intersect(inner_relids, - rinfo->nullable_relids); /* Scan EquivalenceClasses for a match to outervar */ foreach(lc1, root->eq_classes) @@ -2200,7 +2164,6 @@ reconsider_outer_join_clause(PlannerInfo *root, OuterJoinClauseInfo *ojcinfo, innervar, cur_em->em_expr, bms_copy(inner_relids), - bms_copy(inner_nullable_relids), cur_ec->ec_min_security); if (process_equivalence(root, &newrinfo, true)) match = true; @@ -2238,15 +2201,9 @@ reconsider_full_join_clause(PlannerInfo *root, OuterJoinClauseInfo *ojcinfo) left_type, right_type; Relids left_relids, - right_relids, - left_nullable_relids, - right_nullable_relids; + right_relids; ListCell *lc1; - /* Can't use an outerjoin_delayed clause here */ - if (rinfo->outerjoin_delayed) - return false; - /* Extract needed info from the clause */ Assert(is_opclause(rinfo->clause)); opno = ((OpExpr *) rinfo->clause)->opno; @@ -2256,10 +2213,6 @@ reconsider_full_join_clause(PlannerInfo *root, OuterJoinClauseInfo *ojcinfo) rightvar = (Expr *) get_rightop(rinfo->clause); left_relids = rinfo->left_relids; right_relids = rinfo->right_relids; - left_nullable_relids = bms_intersect(left_relids, - rinfo->nullable_relids); - right_nullable_relids = bms_intersect(right_relids, - rinfo->nullable_relids); foreach(lc1, root->eq_classes) { @@ -2361,7 +2314,6 @@ reconsider_full_join_clause(PlannerInfo *root, OuterJoinClauseInfo *ojcinfo) leftvar, cur_em->em_expr, bms_copy(left_relids), - bms_copy(left_nullable_relids), cur_ec->ec_min_security); if (process_equivalence(root, &newrinfo, true)) matchleft = true; @@ -2377,7 +2329,6 @@ reconsider_full_join_clause(PlannerInfo *root, OuterJoinClauseInfo *ojcinfo) rightvar, cur_em->em_expr, bms_copy(right_relids), - bms_copy(right_nullable_relids), cur_ec->ec_min_security); if (process_equivalence(root, &newrinfo, true)) matchright = true; @@ -2675,7 +2626,6 @@ add_child_rel_equivalences(PlannerInfo *root, /* OK, generate transformed child version */ Expr *child_expr; Relids new_relids; - Relids new_nullable_relids; if (parent_rel->reloptkind == RELOPT_BASEREL) { @@ -2705,21 +2655,7 @@ add_child_rel_equivalences(PlannerInfo *root, top_parent_relids); new_relids = bms_add_members(new_relids, child_relids); - /* - * And likewise for nullable_relids. Note this code assumes - * parent and child relids are singletons. - */ - new_nullable_relids = cur_em->em_nullable_relids; - if (bms_overlap(new_nullable_relids, top_parent_relids)) - { - new_nullable_relids = bms_difference(new_nullable_relids, - top_parent_relids); - new_nullable_relids = bms_add_members(new_nullable_relids, - child_relids); - } - - (void) add_eq_member(cur_ec, child_expr, - new_relids, new_nullable_relids, + (void) add_eq_member(cur_ec, child_expr, new_relids, cur_em, cur_em->em_datatype); /* Record this EC index for the child rel */ @@ -2816,7 +2752,6 @@ add_child_join_rel_equivalences(PlannerInfo *root, /* Yes, generate transformed child version */ Expr *child_expr; Relids new_relids; - Relids new_nullable_relids; if (parent_joinrel->reloptkind == RELOPT_JOINREL) { @@ -2847,20 +2782,7 @@ add_child_join_rel_equivalences(PlannerInfo *root, top_parent_relids); new_relids = bms_add_members(new_relids, child_relids); - /* - * For nullable_relids, we must selectively replace parent - * nullable relids with child ones. - */ - new_nullable_relids = cur_em->em_nullable_relids; - if (bms_overlap(new_nullable_relids, top_parent_relids)) - new_nullable_relids = - adjust_child_relids_multilevel(root, - new_nullable_relids, - child_joinrel, - child_joinrel->top_parent); - - (void) add_eq_member(cur_ec, child_expr, - new_relids, new_nullable_relids, + (void) add_eq_member(cur_ec, child_expr, new_relids, cur_em, cur_em->em_datatype); } } |