diff options
Diffstat (limited to 'src/backend/optimizer')
-rw-r--r-- | src/backend/optimizer/path/costsize.c | 54 | ||||
-rw-r--r-- | src/backend/optimizer/path/joinpath.c | 56 | ||||
-rw-r--r-- | src/backend/optimizer/path/joinrels.c | 60 | ||||
-rw-r--r-- | src/backend/optimizer/plan/createplan.c | 136 | ||||
-rw-r--r-- | src/backend/optimizer/plan/planner.c | 2 | ||||
-rw-r--r-- | src/backend/optimizer/util/clauses.c | 7 | ||||
-rw-r--r-- | src/backend/optimizer/util/paramassign.c | 109 | ||||
-rw-r--r-- | src/backend/optimizer/util/pathnode.c | 73 | ||||
-rw-r--r-- | src/backend/optimizer/util/placeholder.c | 40 |
9 files changed, 363 insertions, 174 deletions
diff --git a/src/backend/optimizer/path/costsize.c b/src/backend/optimizer/path/costsize.c index 3d44815ed5a..1f04a2c182c 100644 --- a/src/backend/optimizer/path/costsize.c +++ b/src/backend/optimizer/path/costsize.c @@ -2247,7 +2247,7 @@ append_nonpartial_cost(List *subpaths, int numpaths, int parallel_workers) * Determines and returns the cost of an Append node. */ void -cost_append(AppendPath *apath) +cost_append(AppendPath *apath, PlannerInfo *root) { ListCell *l; @@ -2309,26 +2309,52 @@ cost_append(AppendPath *apath) foreach(l, apath->subpaths) { Path *subpath = (Path *) lfirst(l); - Path sort_path; /* dummy for result of cost_sort */ + int presorted_keys; + Path sort_path; /* dummy for result of + * cost_sort/cost_incremental_sort */ - if (!pathkeys_contained_in(pathkeys, subpath->pathkeys)) + if (!pathkeys_count_contained_in(pathkeys, subpath->pathkeys, + &presorted_keys)) { /* * We'll need to insert a Sort node, so include costs for - * that. We can use the parent's LIMIT if any, since we + * that. We choose to use incremental sort if it is + * enabled and there are presorted keys; otherwise we use + * full sort. + * + * We can use the parent's LIMIT if any, since we * certainly won't pull more than that many tuples from * any child. */ - cost_sort(&sort_path, - NULL, /* doesn't currently need root */ - pathkeys, - subpath->disabled_nodes, - subpath->total_cost, - subpath->rows, - subpath->pathtarget->width, - 0.0, - work_mem, - apath->limit_tuples); + if (enable_incremental_sort && presorted_keys > 0) + { + cost_incremental_sort(&sort_path, + root, + pathkeys, + presorted_keys, + subpath->disabled_nodes, + subpath->startup_cost, + subpath->total_cost, + subpath->rows, + subpath->pathtarget->width, + 0.0, + work_mem, + apath->limit_tuples); + } + else + { + cost_sort(&sort_path, + root, + pathkeys, + subpath->disabled_nodes, + subpath->total_cost, + subpath->rows, + subpath->pathtarget->width, + 0.0, + work_mem, + apath->limit_tuples); + } + subpath = &sort_path; } diff --git a/src/backend/optimizer/path/joinpath.c b/src/backend/optimizer/path/joinpath.c index 26f0336f1e4..ebedc5574ca 100644 --- a/src/backend/optimizer/path/joinpath.c +++ b/src/backend/optimizer/path/joinpath.c @@ -154,13 +154,17 @@ add_paths_to_joinrel(PlannerInfo *root, /* * See if the inner relation is provably unique for this outer rel. * - * We have some special cases: for JOIN_SEMI and JOIN_ANTI, it doesn't - * matter since the executor can make the equivalent optimization anyway; - * we need not expend planner cycles on proofs. For JOIN_UNIQUE_INNER, we - * must be considering a semijoin whose inner side is not provably unique - * (else reduce_unique_semijoins would've simplified it), so there's no - * point in calling innerrel_is_unique. However, if the LHS covers all of - * the semijoin's min_lefthand, then it's appropriate to set inner_unique + * We have some special cases: for JOIN_SEMI, it doesn't matter since the + * executor can make the equivalent optimization anyway. It also doesn't + * help enable use of Memoize, since a semijoin with a provably unique + * inner side should have been reduced to an inner join in that case. + * Therefore, we need not expend planner cycles on proofs. (For + * JOIN_ANTI, although it doesn't help the executor for the same reason, + * it can benefit Memoize paths.) For JOIN_UNIQUE_INNER, we must be + * considering a semijoin whose inner side is not provably unique (else + * reduce_unique_semijoins would've simplified it), so there's no point in + * calling innerrel_is_unique. However, if the LHS covers all of the + * semijoin's min_lefthand, then it's appropriate to set inner_unique * because the path produced by create_unique_path will be unique relative * to the LHS. (If we have an LHS that's only part of the min_lefthand, * that is *not* true.) For JOIN_UNIQUE_OUTER, pass JOIN_INNER to avoid @@ -169,12 +173,6 @@ add_paths_to_joinrel(PlannerInfo *root, switch (jointype) { case JOIN_SEMI: - case JOIN_ANTI: - - /* - * XXX it may be worth proving this to allow a Memoize to be - * considered for Nested Loop Semi/Anti Joins. - */ extra.inner_unique = false; /* well, unproven */ break; case JOIN_UNIQUE_INNER: @@ -715,16 +713,21 @@ get_memoize_path(PlannerInfo *root, RelOptInfo *innerrel, return NULL; /* - * Currently we don't do this for SEMI and ANTI joins unless they're - * marked as inner_unique. This is because nested loop SEMI/ANTI joins - * don't scan the inner node to completion, which will mean memoize cannot - * mark the cache entry as complete. - * - * XXX Currently we don't attempt to mark SEMI/ANTI joins as inner_unique - * = true. Should we? See add_paths_to_joinrel() + * Currently we don't do this for SEMI and ANTI joins, because nested loop + * SEMI/ANTI joins don't scan the inner node to completion, which means + * memoize cannot mark the cache entry as complete. Nor can we mark the + * cache entry as complete after fetching the first inner tuple, because + * if that tuple and the current outer tuple don't satisfy the join + * clauses, a second inner tuple that satisfies the parameters would find + * the cache entry already marked as complete. The only exception is when + * the inner relation is provably unique, as in that case, there won't be + * a second matching tuple and we can safely mark the cache entry as + * complete after fetching the first inner tuple. Note that in such + * cases, the SEMI join should have been reduced to an inner join by + * reduce_unique_semijoins. */ - if (!extra->inner_unique && (jointype == JOIN_SEMI || - jointype == JOIN_ANTI)) + if ((jointype == JOIN_SEMI || jointype == JOIN_ANTI) && + !extra->inner_unique) return NULL; /* @@ -876,16 +879,13 @@ try_nestloop_path(PlannerInfo *root, /* * Check to see if proposed path is still parameterized, and reject if the * parameterization wouldn't be sensible --- unless allow_star_schema_join - * says to allow it anyway. Also, we must reject if have_dangerous_phv - * doesn't like the look of it, which could only happen if the nestloop is - * still parameterized. + * says to allow it anyway. */ required_outer = calc_nestloop_required_outer(outerrelids, outer_paramrels, innerrelids, inner_paramrels); if (required_outer && - ((!bms_overlap(required_outer, extra->param_source_rels) && - !allow_star_schema_join(root, outerrelids, inner_paramrels)) || - have_dangerous_phv(root, outerrelids, inner_paramrels))) + !bms_overlap(required_outer, extra->param_source_rels) && + !allow_star_schema_join(root, outerrelids, inner_paramrels)) { /* Waste no memory when we reject a path here */ bms_free(required_outer); diff --git a/src/backend/optimizer/path/joinrels.c b/src/backend/optimizer/path/joinrels.c index 60d65762b5d..aad41b94009 100644 --- a/src/backend/optimizer/path/joinrels.c +++ b/src/backend/optimizer/path/joinrels.c @@ -565,9 +565,6 @@ join_is_legal(PlannerInfo *root, RelOptInfo *rel1, RelOptInfo *rel2, * Also, if the lateral reference is only indirect, we should reject * the join; whatever rel(s) the reference chain goes through must be * joined to first. - * - * Another case that might keep us from building a valid plan is the - * implementation restriction described by have_dangerous_phv(). */ lateral_fwd = bms_overlap(rel1->relids, rel2->lateral_relids); lateral_rev = bms_overlap(rel2->relids, rel1->lateral_relids); @@ -584,9 +581,6 @@ join_is_legal(PlannerInfo *root, RelOptInfo *rel1, RelOptInfo *rel2, /* check there is a direct reference from rel2 to rel1 */ if (!bms_overlap(rel1->relids, rel2->direct_lateral_relids)) return false; /* only indirect refs, so reject */ - /* check we won't have a dangerous PHV */ - if (have_dangerous_phv(root, rel1->relids, rel2->lateral_relids)) - return false; /* might be unable to handle required PHV */ } else if (lateral_rev) { @@ -599,9 +593,6 @@ join_is_legal(PlannerInfo *root, RelOptInfo *rel1, RelOptInfo *rel2, /* check there is a direct reference from rel1 to rel2 */ if (!bms_overlap(rel2->relids, rel1->direct_lateral_relids)) return false; /* only indirect refs, so reject */ - /* check we won't have a dangerous PHV */ - if (have_dangerous_phv(root, rel2->relids, rel1->lateral_relids)) - return false; /* might be unable to handle required PHV */ } /* @@ -1279,57 +1270,6 @@ has_legal_joinclause(PlannerInfo *root, RelOptInfo *rel) /* - * There's a pitfall for creating parameterized nestloops: suppose the inner - * rel (call it A) has a parameter that is a PlaceHolderVar, and that PHV's - * minimum eval_at set includes the outer rel (B) and some third rel (C). - * We might think we could create a B/A nestloop join that's parameterized by - * C. But we would end up with a plan in which the PHV's expression has to be - * evaluated as a nestloop parameter at the B/A join; and the executor is only - * set up to handle simple Vars as NestLoopParams. Rather than add complexity - * and overhead to the executor for such corner cases, it seems better to - * forbid the join. (Note that we can still make use of A's parameterized - * path with pre-joined B+C as the outer rel. have_join_order_restriction() - * ensures that we will consider making such a join even if there are not - * other reasons to do so.) - * - * So we check whether any PHVs used in the query could pose such a hazard. - * We don't have any simple way of checking whether a risky PHV would actually - * be used in the inner plan, and the case is so unusual that it doesn't seem - * worth working very hard on it. - * - * This needs to be checked in two places. If the inner rel's minimum - * parameterization would trigger the restriction, then join_is_legal() should - * reject the join altogether, because there will be no workable paths for it. - * But joinpath.c has to check again for every proposed nestloop path, because - * the inner path might have more than the minimum parameterization, causing - * some PHV to be dangerous for it that otherwise wouldn't be. - */ -bool -have_dangerous_phv(PlannerInfo *root, - Relids outer_relids, Relids inner_params) -{ - ListCell *lc; - - foreach(lc, root->placeholder_list) - { - PlaceHolderInfo *phinfo = (PlaceHolderInfo *) lfirst(lc); - - if (!bms_is_subset(phinfo->ph_eval_at, inner_params)) - continue; /* ignore, could not be a nestloop param */ - if (!bms_overlap(phinfo->ph_eval_at, outer_relids)) - continue; /* ignore, not relevant to this join */ - if (bms_is_subset(phinfo->ph_eval_at, outer_relids)) - continue; /* safe, it can be eval'd within outerrel */ - /* Otherwise, it's potentially unsafe, so reject the join */ - return true; - } - - /* OK to perform the join */ - return false; -} - - -/* * is_dummy_rel --- has relation been proven empty? */ bool diff --git a/src/backend/optimizer/plan/createplan.c b/src/backend/optimizer/plan/createplan.c index 4ad30b7627e..8a9f1d7a943 100644 --- a/src/backend/optimizer/plan/createplan.c +++ b/src/backend/optimizer/plan/createplan.c @@ -1318,6 +1318,7 @@ create_append_plan(PlannerInfo *root, AppendPath *best_path, int flags) Oid *sortOperators; Oid *collations; bool *nullsFirst; + int presorted_keys; /* * Compute sort column info, and adjust subplan's tlist as needed. @@ -1353,14 +1354,38 @@ create_append_plan(PlannerInfo *root, AppendPath *best_path, int flags) numsortkeys * sizeof(bool)) == 0); /* Now, insert a Sort node if subplan isn't sufficiently ordered */ - if (!pathkeys_contained_in(pathkeys, subpath->pathkeys)) + if (!pathkeys_count_contained_in(pathkeys, subpath->pathkeys, + &presorted_keys)) { - Sort *sort = make_sort(subplan, numsortkeys, + Plan *sort_plan; + + /* + * We choose to use incremental sort if it is enabled and + * there are presorted keys; otherwise we use full sort. + */ + if (enable_incremental_sort && presorted_keys > 0) + { + sort_plan = (Plan *) + make_incrementalsort(subplan, numsortkeys, presorted_keys, sortColIdx, sortOperators, collations, nullsFirst); - label_sort_with_costsize(root, sort, best_path->limit_tuples); - subplan = (Plan *) sort; + label_incrementalsort_with_costsize(root, + (IncrementalSort *) sort_plan, + pathkeys, + best_path->limit_tuples); + } + else + { + sort_plan = (Plan *) make_sort(subplan, numsortkeys, + sortColIdx, sortOperators, + collations, nullsFirst); + + label_sort_with_costsize(root, (Sort *) sort_plan, + best_path->limit_tuples); + } + + subplan = sort_plan; } } @@ -1491,6 +1516,7 @@ create_merge_append_plan(PlannerInfo *root, MergeAppendPath *best_path, Oid *sortOperators; Oid *collations; bool *nullsFirst; + int presorted_keys; /* Build the child plan */ /* Must insist that all children return the same tlist */ @@ -1525,14 +1551,38 @@ create_merge_append_plan(PlannerInfo *root, MergeAppendPath *best_path, numsortkeys * sizeof(bool)) == 0); /* Now, insert a Sort node if subplan isn't sufficiently ordered */ - if (!pathkeys_contained_in(pathkeys, subpath->pathkeys)) + if (!pathkeys_count_contained_in(pathkeys, subpath->pathkeys, + &presorted_keys)) { - Sort *sort = make_sort(subplan, numsortkeys, + Plan *sort_plan; + + /* + * We choose to use incremental sort if it is enabled and there + * are presorted keys; otherwise we use full sort. + */ + if (enable_incremental_sort && presorted_keys > 0) + { + sort_plan = (Plan *) + make_incrementalsort(subplan, numsortkeys, presorted_keys, sortColIdx, sortOperators, collations, nullsFirst); - label_sort_with_costsize(root, sort, best_path->limit_tuples); - subplan = (Plan *) sort; + label_incrementalsort_with_costsize(root, + (IncrementalSort *) sort_plan, + pathkeys, + best_path->limit_tuples); + } + else + { + sort_plan = (Plan *) make_sort(subplan, numsortkeys, + sortColIdx, sortOperators, + collations, nullsFirst); + + label_sort_with_costsize(root, (Sort *) sort_plan, + best_path->limit_tuples); + } + + subplan = sort_plan; } subplans = lappend(subplans, subplan); @@ -4344,13 +4394,16 @@ create_nestloop_plan(PlannerInfo *root, NestLoop *join_plan; Plan *outer_plan; Plan *inner_plan; + Relids outerrelids; List *tlist = build_path_tlist(root, &best_path->jpath.path); List *joinrestrictclauses = best_path->jpath.joinrestrictinfo; List *joinclauses; List *otherclauses; - Relids outerrelids; List *nestParams; + List *outer_tlist; + bool outer_parallel_safe; Relids saveOuterRels = root->curOuterRels; + ListCell *lc; /* * If the inner path is parameterized by the topmost parent of the outer @@ -4372,8 +4425,8 @@ create_nestloop_plan(PlannerInfo *root, outer_plan = create_plan_recurse(root, best_path->jpath.outerjoinpath, 0); /* For a nestloop, include outer relids in curOuterRels for inner side */ - root->curOuterRels = bms_union(root->curOuterRels, - best_path->jpath.outerjoinpath->parent->relids); + outerrelids = best_path->jpath.outerjoinpath->parent->relids; + root->curOuterRels = bms_union(root->curOuterRels, outerrelids); inner_plan = create_plan_recurse(root, best_path->jpath.innerjoinpath, 0); @@ -4412,9 +4465,66 @@ create_nestloop_plan(PlannerInfo *root, * Identify any nestloop parameters that should be supplied by this join * node, and remove them from root->curOuterParams. */ - outerrelids = best_path->jpath.outerjoinpath->parent->relids; - nestParams = identify_current_nestloop_params(root, outerrelids); + nestParams = identify_current_nestloop_params(root, + outerrelids, + PATH_REQ_OUTER((Path *) best_path)); + + /* + * While nestloop parameters that are Vars had better be available from + * the outer_plan already, there are edge cases where nestloop parameters + * that are PHVs won't be. In such cases we must add them to the + * outer_plan's tlist, since the executor's NestLoopParam machinery + * requires the params to be simple outer-Var references to that tlist. + * (This is cheating a little bit, because the outer path's required-outer + * relids might not be enough to allow evaluating such a PHV. But in + * practice, if we could have evaluated the PHV at the nestloop node, we + * can do so in the outer plan too.) + */ + outer_tlist = outer_plan->targetlist; + outer_parallel_safe = outer_plan->parallel_safe; + foreach(lc, nestParams) + { + NestLoopParam *nlp = (NestLoopParam *) lfirst(lc); + PlaceHolderVar *phv; + TargetEntry *tle; + + if (IsA(nlp->paramval, Var)) + continue; /* nothing to do for simple Vars */ + /* Otherwise it must be a PHV */ + phv = castNode(PlaceHolderVar, nlp->paramval); + + if (tlist_member((Expr *) phv, outer_tlist)) + continue; /* already available */ + + /* + * It's possible that nestloop parameter PHVs selected to evaluate + * here contain references to surviving root->curOuterParams items + * (that is, they reference values that will be supplied by some + * higher-level nestloop). Those need to be converted to Params now. + * Note: it's safe to do this after the tlist_member() check, because + * equal() won't pay attention to phv->phexpr. + */ + phv->phexpr = (Expr *) replace_nestloop_params(root, + (Node *) phv->phexpr); + + /* Make a shallow copy of outer_tlist, if we didn't already */ + if (outer_tlist == outer_plan->targetlist) + outer_tlist = list_copy(outer_tlist); + /* ... and add the needed expression */ + tle = makeTargetEntry((Expr *) copyObject(phv), + list_length(outer_tlist) + 1, + NULL, + true); + outer_tlist = lappend(outer_tlist, tle); + /* ... and track whether tlist is (still) parallel-safe */ + if (outer_parallel_safe) + outer_parallel_safe = is_parallel_safe(root, (Node *) phv); + } + if (outer_tlist != outer_plan->targetlist) + outer_plan = change_plan_targetlist(outer_plan, outer_tlist, + outer_parallel_safe); + /* And finally, we can build the join plan node */ join_plan = make_nestloop(tlist, joinclauses, otherclauses, diff --git a/src/backend/optimizer/plan/planner.c b/src/backend/optimizer/plan/planner.c index ff65867eebe..549aedcfa99 100644 --- a/src/backend/optimizer/plan/planner.c +++ b/src/backend/optimizer/plan/planner.c @@ -6879,7 +6879,7 @@ plan_cluster_use_sort(Oid tableOid, Oid indexOid) * * tableOid is the table on which the index is to be built. indexOid is the * OID of an index to be created or reindexed (which must be an index with - * support for parallel builds - currently btree or BRIN). + * support for parallel builds - currently btree, GIN, or BRIN). * * Return value is the number of parallel worker processes to request. It * may be unsafe to proceed if this is 0. Note that this does not include the diff --git a/src/backend/optimizer/util/clauses.c b/src/backend/optimizer/util/clauses.c index 26a3e050086..f45131c34c5 100644 --- a/src/backend/optimizer/util/clauses.c +++ b/src/backend/optimizer/util/clauses.c @@ -3333,6 +3333,13 @@ eval_const_expressions_mutator(Node *node, -1, coalesceexpr->coalescecollid); + /* + * If there's exactly one surviving argument, we no longer + * need COALESCE at all: the result is that argument + */ + if (list_length(newargs) == 1) + return (Node *) linitial(newargs); + newcoalesce = makeNode(CoalesceExpr); newcoalesce->coalescetype = coalesceexpr->coalescetype; newcoalesce->coalescecollid = coalesceexpr->coalescecollid; diff --git a/src/backend/optimizer/util/paramassign.c b/src/backend/optimizer/util/paramassign.c index 3bd3ce37c8f..4c13c5931b4 100644 --- a/src/backend/optimizer/util/paramassign.c +++ b/src/backend/optimizer/util/paramassign.c @@ -599,38 +599,46 @@ process_subquery_nestloop_params(PlannerInfo *root, List *subplan_params) } /* - * Identify any NestLoopParams that should be supplied by a NestLoop plan - * node with the specified lefthand rels. Remove them from the active - * root->curOuterParams list and return them as the result list. + * Identify any NestLoopParams that should be supplied by a NestLoop + * plan node with the specified lefthand rels and required-outer rels. + * Remove them from the active root->curOuterParams list and return + * them as the result list. * - * XXX Here we also hack up the returned Vars and PHVs so that they do not - * contain nullingrel sets exceeding what is available from the outer side. - * This is needed if we have applied outer join identity 3, - * (A leftjoin B on (Pab)) leftjoin C on (Pb*c) - * = A leftjoin (B leftjoin C on (Pbc)) on (Pab) - * and C contains lateral references to B. It's still safe to apply the - * identity, but the parser will have created those references in the form - * "b*" (i.e., with varnullingrels listing the A/B join), while what we will - * have available from the nestloop's outer side is just "b". We deal with - * that here by stripping the nullingrels down to what is available from the - * outer side according to leftrelids. - * - * That fixes matters for the case of forward application of identity 3. - * If the identity was applied in the reverse direction, we will have - * parameter Vars containing too few nullingrel bits rather than too many. - * Currently, that causes no problems because setrefs.c applies only a - * subset check to nullingrels in NestLoopParams, but we'd have to work - * harder if we ever want to tighten that check. This is all pretty annoying - * because it greatly weakens setrefs.c's cross-check, but the alternative + * Vars and PHVs appearing in the result list must have nullingrel sets + * that could validly appear in the lefthand rel's output. Ordinarily that + * would be true already, but if we have applied outer join identity 3, + * there could be more or fewer nullingrel bits in the nodes appearing in + * curOuterParams than are in the nominal leftrelids. We deal with that by + * forcing their nullingrel sets to include exactly the outer-join relids + * that appear in leftrelids and can null the respective Var or PHV. + * This fix is a bit ad-hoc and intellectually unsatisfactory, because it's + * essentially jumping to the conclusion that we've placed evaluation of + * the nestloop parameters correctly, and thus it defeats the intent of the + * subsequent nullingrel cross-checks in setrefs.c. But the alternative * seems to be to generate multiple versions of each laterally-parameterized * subquery, which'd be unduly expensive. */ List * -identify_current_nestloop_params(PlannerInfo *root, Relids leftrelids) +identify_current_nestloop_params(PlannerInfo *root, + Relids leftrelids, + Relids outerrelids) { List *result; + Relids allleftrelids; ListCell *cell; + /* + * We'll be able to evaluate a PHV in the lefthand path if it uses the + * lefthand rels plus any available required-outer rels. But don't do so + * if it uses *only* required-outer rels; in that case it should be + * evaluated higher in the tree. For Vars, no such hair-splitting is + * necessary since they depend on only one relid. + */ + if (outerrelids) + allleftrelids = bms_union(leftrelids, outerrelids); + else + allleftrelids = leftrelids; + result = NIL; foreach(cell, root->curOuterParams) { @@ -646,25 +654,60 @@ identify_current_nestloop_params(PlannerInfo *root, Relids leftrelids) bms_is_member(nlp->paramval->varno, leftrelids)) { Var *var = (Var *) nlp->paramval; + RelOptInfo *rel = root->simple_rel_array[var->varno]; root->curOuterParams = foreach_delete_current(root->curOuterParams, cell); - var->varnullingrels = bms_intersect(var->varnullingrels, + var->varnullingrels = bms_intersect(rel->nulling_relids, leftrelids); result = lappend(result, nlp); } - else if (IsA(nlp->paramval, PlaceHolderVar) && - bms_is_subset(find_placeholder_info(root, - (PlaceHolderVar *) nlp->paramval)->ph_eval_at, - leftrelids)) + else if (IsA(nlp->paramval, PlaceHolderVar)) { PlaceHolderVar *phv = (PlaceHolderVar *) nlp->paramval; + PlaceHolderInfo *phinfo = find_placeholder_info(root, phv); + Relids eval_at = phinfo->ph_eval_at; - root->curOuterParams = foreach_delete_current(root->curOuterParams, - cell); - phv->phnullingrels = bms_intersect(phv->phnullingrels, - leftrelids); - result = lappend(result, nlp); + if (bms_is_subset(eval_at, allleftrelids) && + bms_overlap(eval_at, leftrelids)) + { + root->curOuterParams = foreach_delete_current(root->curOuterParams, + cell); + + /* + * Deal with an edge case: if the PHV was pulled up out of a + * subquery and it contains a subquery that was originally + * pushed down from this query level, then that will still be + * represented as a SubLink, because SS_process_sublinks won't + * recurse into outer PHVs, so it didn't get transformed + * during expression preprocessing in the subquery. We need a + * version of the PHV that has a SubPlan, which we can get + * from the current query level's placeholder_list. This is + * quite grotty of course, but dealing with it earlier in the + * handling of subplan params would be just as grotty, and it + * might end up being a waste of cycles if we don't decide to + * treat the PHV as a NestLoopParam. (Perhaps that whole + * mechanism should be redesigned someday, but today is not + * that day.) + */ + if (root->parse->hasSubLinks) + { + phv = copyObject(phinfo->ph_var); + + /* + * The ph_var will have empty nullingrels, but that + * doesn't matter since we're about to overwrite + * phv->phnullingrels. Other fields should be OK already. + */ + nlp->paramval = (Var *) phv; + } + + phv->phnullingrels = + bms_intersect(get_placeholder_nulling_relids(root, phinfo), + leftrelids); + + result = lappend(result, nlp); + } } } return result; diff --git a/src/backend/optimizer/util/pathnode.c b/src/backend/optimizer/util/pathnode.c index e0192d4a491..9cc602788ea 100644 --- a/src/backend/optimizer/util/pathnode.c +++ b/src/backend/optimizer/util/pathnode.c @@ -1404,12 +1404,12 @@ create_append_path(PlannerInfo *root, pathnode->path.total_cost = child->total_cost; } else - cost_append(pathnode); + cost_append(pathnode, root); /* Must do this last, else cost_append complains */ pathnode->path.pathkeys = child->pathkeys; } else - cost_append(pathnode); + cost_append(pathnode, root); /* If the caller provided a row estimate, override the computed value. */ if (rows >= 0) @@ -1515,6 +1515,9 @@ create_merge_append_path(PlannerInfo *root, foreach(l, subpaths) { Path *subpath = (Path *) lfirst(l); + int presorted_keys; + Path sort_path; /* dummy for result of + * cost_sort/cost_incremental_sort */ /* All child paths should be unparameterized */ Assert(bms_is_empty(PATH_REQ_OUTER(subpath))); @@ -1523,32 +1526,52 @@ create_merge_append_path(PlannerInfo *root, pathnode->path.parallel_safe = pathnode->path.parallel_safe && subpath->parallel_safe; - if (pathkeys_contained_in(pathkeys, subpath->pathkeys)) + if (!pathkeys_count_contained_in(pathkeys, subpath->pathkeys, + &presorted_keys)) { - /* Subpath is adequately ordered, we won't need to sort it */ - input_disabled_nodes += subpath->disabled_nodes; - input_startup_cost += subpath->startup_cost; - input_total_cost += subpath->total_cost; - } - else - { - /* We'll need to insert a Sort node, so include cost for that */ - Path sort_path; /* dummy for result of cost_sort */ + /* + * We'll need to insert a Sort node, so include costs for that. We + * choose to use incremental sort if it is enabled and there are + * presorted keys; otherwise we use full sort. + * + * We can use the parent's LIMIT if any, since we certainly won't + * pull more than that many tuples from any child. + */ + if (enable_incremental_sort && presorted_keys > 0) + { + cost_incremental_sort(&sort_path, + root, + pathkeys, + presorted_keys, + subpath->disabled_nodes, + subpath->startup_cost, + subpath->total_cost, + subpath->rows, + subpath->pathtarget->width, + 0.0, + work_mem, + pathnode->limit_tuples); + } + else + { + cost_sort(&sort_path, + root, + pathkeys, + subpath->disabled_nodes, + subpath->total_cost, + subpath->rows, + subpath->pathtarget->width, + 0.0, + work_mem, + pathnode->limit_tuples); + } - cost_sort(&sort_path, - root, - pathkeys, - subpath->disabled_nodes, - subpath->total_cost, - subpath->rows, - subpath->pathtarget->width, - 0.0, - work_mem, - pathnode->limit_tuples); - input_disabled_nodes += sort_path.disabled_nodes; - input_startup_cost += sort_path.startup_cost; - input_total_cost += sort_path.total_cost; + subpath = &sort_path; } + + input_disabled_nodes += subpath->disabled_nodes; + input_startup_cost += subpath->startup_cost; + input_total_cost += subpath->total_cost; } /* diff --git a/src/backend/optimizer/util/placeholder.c b/src/backend/optimizer/util/placeholder.c index 41a4c81e94a..e1cd00a72fb 100644 --- a/src/backend/optimizer/util/placeholder.c +++ b/src/backend/optimizer/util/placeholder.c @@ -545,3 +545,43 @@ contain_placeholder_references_walker(Node *node, return expression_tree_walker(node, contain_placeholder_references_walker, context); } + +/* + * Compute the set of outer-join relids that can null a placeholder. + * + * This is analogous to RelOptInfo.nulling_relids for Vars, but we compute it + * on-the-fly rather than saving it somewhere. Currently the value is needed + * at most once per query, so there's little value in doing otherwise. If it + * ever gains more widespread use, perhaps we should cache the result in + * PlaceHolderInfo. + */ +Relids +get_placeholder_nulling_relids(PlannerInfo *root, PlaceHolderInfo *phinfo) +{ + Relids result = NULL; + int relid = -1; + + /* + * Form the union of all potential nulling OJs for each baserel included + * in ph_eval_at. + */ + while ((relid = bms_next_member(phinfo->ph_eval_at, relid)) > 0) + { + RelOptInfo *rel = root->simple_rel_array[relid]; + + /* ignore the RTE_GROUP RTE */ + if (relid == root->group_rtindex) + continue; + + if (rel == NULL) /* must be an outer join */ + { + Assert(bms_is_member(relid, root->outer_join_rels)); + continue; + } + result = bms_add_members(result, rel->nulling_relids); + } + + /* Now remove any OJs already included in ph_eval_at, and we're done. */ + result = bms_del_members(result, phinfo->ph_eval_at); + return result; +} |