/*
* add_child_rel_equivalences
- * Search for EC members that reference the parent_rel, and
+ * Search for EC members that reference the root parent of child_rel, and
* add transformed members referencing the child_rel.
*
* Note that this function won't be called at all unless we have at least some
*
* parent_rel and child_rel could be derived from appinfo, but since the
* caller has already computed them, we might as well just pass them in.
+ *
+ * The passed-in AppendRelInfo is not used when the parent_rel is not a
+ * top-level baserel, since it shows the mapping from the parent_rel but
+ * we need to translate EC expressions that refer to the top-level parent.
+ * Using it is faster than using adjust_appendrel_attrs_multilevel(), though,
+ * so we prefer it when we can.
*/
void
add_child_rel_equivalences(PlannerInfo *root,
RelOptInfo *parent_rel,
RelOptInfo *child_rel)
{
+ Relids top_parent_relids = child_rel->top_parent_relids;
+ Relids child_relids = child_rel->relids;
ListCell *lc1;
+ Assert(IS_SIMPLE_REL(parent_rel));
+
foreach(lc1, root->eq_classes)
{
EquivalenceClass *cur_ec = (EquivalenceClass *) lfirst(lc1);
* No point in searching if child's topmost parent rel is not
* mentioned in eclass.
*/
- if (!bms_is_subset(child_rel->top_parent_relids, cur_ec->ec_relids))
+ if (!bms_is_subset(top_parent_relids, cur_ec->ec_relids))
continue;
foreach(lc2, cur_ec->ec_members)
* 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.
+ * 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 */
/* Does this member reference child's topmost parent rel? */
- if (bms_overlap(cur_em->em_relids, child_rel->top_parent_relids))
+ if (bms_overlap(cur_em->em_relids, top_parent_relids))
{
/* Yes, generate transformed child version */
Expr *child_expr;
child_expr = (Expr *)
adjust_appendrel_attrs_multilevel(root,
(Node *) cur_em->em_expr,
- child_rel->relids,
- child_rel->top_parent_relids);
+ child_relids,
+ top_parent_relids);
}
/*
* don't want the child member to be marked as constant.
*/
new_relids = bms_difference(cur_em->em_relids,
- child_rel->top_parent_relids);
- new_relids = bms_add_members(new_relids, child_rel->relids);
+ 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,
- child_rel->top_parent_relids))
+ if (bms_overlap(new_nullable_relids, top_parent_relids))
{
new_nullable_relids = bms_difference(new_nullable_relids,
- child_rel->top_parent_relids);
+ top_parent_relids);
new_nullable_relids = bms_add_members(new_nullable_relids,
- child_rel->relids);
+ child_relids);
+ }
+
+ (void) add_eq_member(cur_ec, child_expr,
+ new_relids, new_nullable_relids,
+ true, cur_em->em_datatype);
+ }
+ }
+ }
+}
+
+/*
+ * add_child_join_rel_equivalences
+ * Like add_child_rel_equivalences(), but for joinrels
+ *
+ * Here we find the ECs relevant to the top parent joinrel and add transformed
+ * member expressions that refer to this child joinrel.
+ *
+ * Note that this function won't be called at all unless we have at least some
+ * reason to believe that the EC members it generates will be useful.
+ */
+void
+add_child_join_rel_equivalences(PlannerInfo *root,
+ int nappinfos, AppendRelInfo **appinfos,
+ RelOptInfo *parent_joinrel,
+ RelOptInfo *child_joinrel)
+{
+ Relids top_parent_relids = child_joinrel->top_parent_relids;
+ Relids child_relids = child_joinrel->relids;
+ ListCell *lc1;
+
+ Assert(IS_JOIN_REL(child_joinrel) && IS_JOIN_REL(parent_joinrel));
+
+ foreach(lc1, root->eq_classes)
+ {
+ EquivalenceClass *cur_ec = (EquivalenceClass *) lfirst(lc1);
+ ListCell *lc2;
+
+ /*
+ * If this EC contains a volatile expression, then generating child
+ * EMs would be downright dangerous, so skip it. We rely on a
+ * volatile EC having only one EM.
+ */
+ if (cur_ec->ec_has_volatile)
+ continue;
+
+ /*
+ * No point in searching if child's topmost parent rel is not
+ * mentioned in eclass.
+ */
+ if (!bms_overlap(top_parent_relids, cur_ec->ec_relids))
+ continue;
+
+ foreach(lc2, cur_ec->ec_members)
+ {
+ EquivalenceMember *cur_em = (EquivalenceMember *) lfirst(lc2);
+
+ 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 */
+
+ /*
+ * We may ignore expressions that reference a single baserel,
+ * because add_child_rel_equivalences should have handled them.
+ */
+ if (bms_membership(cur_em->em_relids) != BMS_MULTIPLE)
+ continue;
+
+ /* Does this member reference child's topmost parent rel? */
+ if (bms_overlap(cur_em->em_relids, top_parent_relids))
+ {
+ /* Yes, generate transformed child version */
+ Expr *child_expr;
+ Relids new_relids;
+ Relids new_nullable_relids;
+
+ if (parent_joinrel->reloptkind == RELOPT_JOINREL)
+ {
+ /* Simple single-level transformation */
+ child_expr = (Expr *)
+ adjust_appendrel_attrs(root,
+ (Node *) cur_em->em_expr,
+ nappinfos, appinfos);
}
+ else
+ {
+ /* Must do multi-level transformation */
+ Assert(parent_joinrel->reloptkind == RELOPT_OTHER_JOINREL);
+ child_expr = (Expr *)
+ adjust_appendrel_attrs_multilevel(root,
+ (Node *) cur_em->em_expr,
+ child_relids,
+ top_parent_relids);
+ }
+
+ /*
+ * Transform em_relids to match. Note we do *not* do
+ * pull_varnos(child_expr) here, as for example the
+ * transformation might have substituted a constant, but we
+ * don't want the child member to be marked as constant.
+ */
+ new_relids = bms_difference(cur_em->em_relids,
+ 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_relids,
+ top_parent_relids);
(void) add_eq_member(cur_ec, child_expr,
new_relids, new_nullable_relids,
550 | |
(12 rows)
+-- bug with inadequate sort key representation
+SET enable_partitionwise_aggregate TO true;
+SET enable_hashjoin TO false;
+EXPLAIN (COSTS OFF)
+SELECT a, b FROM prt1 FULL JOIN prt2 p2(b,a,c) USING(a,b)
+ WHERE a BETWEEN 490 AND 510
+ GROUP BY 1, 2 ORDER BY 1, 2;
+ QUERY PLAN
+-------------------------------------------------------------------------------------------------------------------
+ Group
+ Group Key: (COALESCE(prt1_p1.a, p2.a)), (COALESCE(prt1_p1.b, p2.b))
+ -> Merge Append
+ Sort Key: (COALESCE(prt1_p1.a, p2.a)), (COALESCE(prt1_p1.b, p2.b))
+ -> Group
+ Group Key: (COALESCE(prt1_p1.a, p2.a)), (COALESCE(prt1_p1.b, p2.b))
+ -> Sort
+ Sort Key: (COALESCE(prt1_p1.a, p2.a)), (COALESCE(prt1_p1.b, p2.b))
+ -> Merge Full Join
+ Merge Cond: ((prt1_p1.a = p2.a) AND (prt1_p1.b = p2.b))
+ Filter: ((COALESCE(prt1_p1.a, p2.a) >= 490) AND (COALESCE(prt1_p1.a, p2.a) <= 510))
+ -> Sort
+ Sort Key: prt1_p1.a, prt1_p1.b
+ -> Seq Scan on prt1_p1
+ -> Sort
+ Sort Key: p2.a, p2.b
+ -> Seq Scan on prt2_p1 p2
+ -> Group
+ Group Key: (COALESCE(prt1_p2.a, p2_1.a)), (COALESCE(prt1_p2.b, p2_1.b))
+ -> Sort
+ Sort Key: (COALESCE(prt1_p2.a, p2_1.a)), (COALESCE(prt1_p2.b, p2_1.b))
+ -> Merge Full Join
+ Merge Cond: ((prt1_p2.a = p2_1.a) AND (prt1_p2.b = p2_1.b))
+ Filter: ((COALESCE(prt1_p2.a, p2_1.a) >= 490) AND (COALESCE(prt1_p2.a, p2_1.a) <= 510))
+ -> Sort
+ Sort Key: prt1_p2.a, prt1_p2.b
+ -> Seq Scan on prt1_p2
+ -> Sort
+ Sort Key: p2_1.a, p2_1.b
+ -> Seq Scan on prt2_p2 p2_1
+ -> Group
+ Group Key: (COALESCE(prt1_p3.a, p2_2.a)), (COALESCE(prt1_p3.b, p2_2.b))
+ -> Sort
+ Sort Key: (COALESCE(prt1_p3.a, p2_2.a)), (COALESCE(prt1_p3.b, p2_2.b))
+ -> Merge Full Join
+ Merge Cond: ((prt1_p3.a = p2_2.a) AND (prt1_p3.b = p2_2.b))
+ Filter: ((COALESCE(prt1_p3.a, p2_2.a) >= 490) AND (COALESCE(prt1_p3.a, p2_2.a) <= 510))
+ -> Sort
+ Sort Key: prt1_p3.a, prt1_p3.b
+ -> Seq Scan on prt1_p3
+ -> Sort
+ Sort Key: p2_2.a, p2_2.b
+ -> Seq Scan on prt2_p3 p2_2
+(43 rows)
+
+SELECT a, b FROM prt1 FULL JOIN prt2 p2(b,a,c) USING(a,b)
+ WHERE a BETWEEN 490 AND 510
+ GROUP BY 1, 2 ORDER BY 1, 2;
+ a | b
+-----+----
+ 490 | 15
+ 492 | 17
+ 494 | 19
+ 495 | 20
+ 496 | 21
+ 498 | 23
+ 500 | 0
+ 501 | 1
+ 502 | 2
+ 504 | 4
+ 506 | 6
+ 507 | 7
+ 508 | 8
+ 510 | 10
+(14 rows)
+
+RESET enable_partitionwise_aggregate;
+RESET enable_hashjoin;
--
-- partitioned by expression
--
projects / postgresql.git / commitdiff