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Fix run-time partition pruning for appends with multiple source rels.

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The previous coding here supposed that if run-time partitioning applied to
a particular Append/MergeAppend plan, then all child plans of that node
must be members of a single partitioning hierarchy.  This is totally wrong,
since an Append could be formed from a UNION ALL: we could have multiple
hierarchies sharing the same Append, or child plans that aren't part of any
hierarchy.

To fix, restructure the related plan-time and execution-time data
structures so that we can have a separate list or array for each
partitioning hierarchy.  Also track subplans that are not part of any
hierarchy, and make sure they don't get pruned.

Per reports from Phil Florent and others.  Back-patch to v11, since
the bug originated there.

David Rowley, with a lot of cosmetic adjustments by me; thanks also
to Amit Langote for review.

Discussion: https://postgr.es/m/HE1PR03MB17068BB27404C90B5B788BCABA7B0@HE1PR03MB1706.eurprd03.prod.outlook.com
This commit is contained in:
Tom Lane
2018-08-01 19:42:46 -04:00
parent c40489e449
commit 1c2cb2744b
16 changed files with 846 additions and 291 deletions
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27
src/backend/optimizer/path/allpaths.c
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@ -1388,7 +1388,6 @@ add_paths_to_append_rel(PlannerInfo *root, RelOptInfo *rel,
List *all_child_outers = NIL;
ListCell *l;
List *partitioned_rels = NIL;
bool build_partitioned_rels = false;
double partial_rows = -1;
/* If appropriate, consider parallel append */
@ -1413,10 +1412,11 @@ add_paths_to_append_rel(PlannerInfo *root, RelOptInfo *rel,
if (rel->part_scheme != NULL)
{
if (IS_SIMPLE_REL(rel))
partitioned_rels = rel->partitioned_child_rels;
partitioned_rels = list_make1(rel->partitioned_child_rels);
else if (IS_JOIN_REL(rel))
{
int relid = -1;
List *partrels = NIL;
/*
* For a partitioned joinrel, concatenate the component rels'
@ -1430,16 +1430,16 @@ add_paths_to_append_rel(PlannerInfo *root, RelOptInfo *rel,
component = root->simple_rel_array[relid];
Assert(component->part_scheme != NULL);
Assert(list_length(component->partitioned_child_rels) >= 1);
partitioned_rels =
list_concat(partitioned_rels,
partrels =
list_concat(partrels,
list_copy(component->partitioned_child_rels));
}
partitioned_rels = list_make1(partrels);
}
Assert(list_length(partitioned_rels) >= 1);
}
else if (rel->rtekind == RTE_SUBQUERY)
build_partitioned_rels = true;
/*
* For every non-dummy child, remember the cheapest path. Also, identify
@ -1453,17 +1453,12 @@ add_paths_to_append_rel(PlannerInfo *root, RelOptInfo *rel,
Path *cheapest_partial_path = NULL;
/*
* If we need to build partitioned_rels, accumulate the partitioned
* rels for this child. We must ensure that parents are always listed
* before their child partitioned tables.
* For UNION ALLs with non-empty partitioned_child_rels, accumulate
* the Lists of child relations.
*/
if (build_partitioned_rels)
{
List *cprels = childrel->partitioned_child_rels;
partitioned_rels = list_concat(partitioned_rels,
list_copy(cprels));
}
if (rel->rtekind == RTE_SUBQUERY && childrel->partitioned_child_rels != NIL)
partitioned_rels = lappend(partitioned_rels,
childrel->partitioned_child_rels);
/*
* If child has an unparameterized cheapest-total path, add that to