On Sat, Oct 7, 2017 at 1:04 AM, Robert Haas <robertmh...@gmail.com> wrote:
>
> Committed. I hope that makes things less red rather than more,
> because I'm going to be AFK for a few hours anyway.
>
Here's the last patch, dealing with the dummy relations, rebased. With
this fix every join order of a partitioned join can be considered
partitioned. (This wasn't the case earlier when dummy relation was
involved.). So, we can allocate the child-join RelOptInfo array in
build_joinrel_partition_info(), instead of waiting for an appropriate
pair to arrive in try_partition_wise_join().
--
Best Wishes,
Ashutosh Bapat
EnterpriseDB Corporation
The Postgres Database Company
From 4bf8ca38719aee730ed57a7f14522384b1ced7b0 Mon Sep 17 00:00:00 2001
From: Ashutosh Bapat <ashutosh.ba...@enterprisedb.com>
Date: Tue, 29 Aug 2017 12:37:14 +0530
Subject: [PATCH] Support partition-wise join for dummy partitioned relation.
Current partition-wise join implementation treats dummy relations as
unpartitioned since the child relations may not be marked dummy and may not
have their pathlists set (See set_rel_size() and set_rel_pathlist()). Since
children do not have paths set, they can not be used to form a child-join. This
patch marks the children of dummy partitioned relations as dummy, thus allowing
partition-wise join when one of the joining relations is dummy.
If the dummy partitioned relation is a base relation, its children are base
relations as well and we will be marking base relation dummy during join
planning. But this shouldn't be a problem since populate_joinrel_with_paths()
already does that to an inner relation of left join.
Ashutosh Bapat.
---
src/backend/optimizer/path/allpaths.c | 7 +------
src/backend/optimizer/path/joinrels.c | 24 ++++++++++++------------
src/backend/optimizer/util/relnode.c | 5 +++++
3 files changed, 18 insertions(+), 18 deletions(-)
diff --git a/src/backend/optimizer/path/allpaths.c b/src/backend/optimizer/path/allpaths.c
index 5535b63..b46fb5b 100644
--- a/src/backend/optimizer/path/allpaths.c
+++ b/src/backend/optimizer/path/allpaths.c
@@ -3261,12 +3261,7 @@ generate_partition_wise_join_paths(PlannerInfo *root, RelOptInfo *rel)
if (IS_DUMMY_REL(rel))
return;
- /*
- * Nothing to do if the relation is not partitioned. An outer join
- * relation which had empty inner relation in every pair will have rest of
- * the partitioning properties set except the child-join RelOptInfos. See
- * try_partition_wise_join() for more explanation.
- */
+ /* Nothing to do if the relation is not partitioned. */
if (rel->nparts <= 0 || rel->part_rels == NULL)
return;
diff --git a/src/backend/optimizer/path/joinrels.c b/src/backend/optimizer/path/joinrels.c
index 2b868c5..1578dea 100644
--- a/src/backend/optimizer/path/joinrels.c
+++ b/src/backend/optimizer/path/joinrels.c
@@ -1321,14 +1321,19 @@ try_partition_wise_join(PlannerInfo *root, RelOptInfo *rel1, RelOptInfo *rel2,
/*
* set_rel_pathlist() may not create paths in children of an empty
- * partitioned table and so we can not add paths to child-joins. So, deem
- * such a join as unpartitioned. When a partitioned relation is deemed
- * empty because all its children are empty, dummy path will be set in
- * each of the children. In such a case we could still consider the join
- * as partitioned, but it might not help much.
+ * partitioned table. Mark such children as dummy so that we can add paths
+ * to child-joins.
*/
- if (IS_DUMMY_REL(rel1) || IS_DUMMY_REL(rel2))
- return;
+ if (IS_DUMMY_REL(rel1))
+ {
+ for (cnt_parts = 0; cnt_parts < rel1->nparts; cnt_parts++)
+ mark_dummy_rel(rel1->part_rels[cnt_parts]);
+ }
+ if (IS_DUMMY_REL(rel2))
+ {
+ for (cnt_parts = 0; cnt_parts < rel2->nparts; cnt_parts++)
+ mark_dummy_rel(rel2->part_rels[cnt_parts]);
+ }
/*
* Since this join relation is partitioned, all the base relations
@@ -1361,11 +1366,6 @@ try_partition_wise_join(PlannerInfo *root, RelOptInfo *rel1, RelOptInfo *rel2,
nparts = joinrel->nparts;
- /* Allocate space to hold child-joins RelOptInfos, if not already done. */
- if (!joinrel->part_rels)
- joinrel->part_rels =
- (RelOptInfo **) palloc0(sizeof(RelOptInfo *) * nparts);
-
/*
* Create child-join relations for this partitioned join, if those don't
* exist. Add paths to child-joins for a pair of child relations
diff --git a/src/backend/optimizer/util/relnode.c b/src/backend/optimizer/util/relnode.c
index 3bd1063..21fd29f 100644
--- a/src/backend/optimizer/util/relnode.c
+++ b/src/backend/optimizer/util/relnode.c
@@ -1746,4 +1746,9 @@ build_joinrel_partition_info(RelOptInfo *joinrel, RelOptInfo *outer_rel,
joinrel->partexprs[cnt] = partexpr;
joinrel->nullable_partexprs[cnt] = nullable_partexpr;
}
+
+ /* Allocate space to hold child-joins RelOptInfos. */
+ joinrel->part_rels =
+ (RelOptInfo **) palloc0(sizeof(RelOptInfo *) * joinrel->nparts);
+
}
--
1.7.9.5
--
Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org)
To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-hackers
