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Fix JOINs on varchar columns with subquery pushdown 

Fixes #379

Varchar VAR struct is wrapped in RELABELTYPE struct inside PostgreSQL code and
IsPartitionColumnRecursive function considers only VAR types so returning false
for varchar.

This change adds strip_implicit_coercions() call to the columnExpression in
IsPartitionColumnRecursive function so that we get rid of implicit coercions like
RELABELTYPE are stripped to VAR.
pull/426/head
eren 2016-04-08 11:51:37 +03:00 committed by Jason Petersen
parent 399b5738b0
commit 448527c3af
No known key found for this signature in database
GPG Key ID: 9F1D3510D110ABA9
3 changed files with 67 additions and 4 deletions
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9
src/backend/distributed/planner/multi_logical_optimizer.c
View File

@ -2907,14 +2907,15 @@ IsPartitionColumnRecursive(Expr *columnExpression, Query *query)
List *rangetableList = query->rtable;
Index rangeTableEntryIndex = 0;
RangeTblEntry *rangeTableEntry = NULL;
Expr *strippedColumnExpression = strip_implicit_coercions(columnExpression);
if (IsA(columnExpression, Var))
if (IsA(strippedColumnExpression, Var))
{
candidateColumn = (Var *) columnExpression;
candidateColumn = (Var *) strippedColumnExpression;
}
else if (IsA(columnExpression, FieldSelect))
else if (IsA(strippedColumnExpression, FieldSelect))
{
FieldSelect *compositeField = (FieldSelect *) columnExpression;
FieldSelect *compositeField = (FieldSelect *) strippedColumnExpression;
Expr *fieldExpression = compositeField->arg;
if (IsA(fieldExpression, Var))

30
src/test/regress/input/multi_subquery.source
View File

@ -319,6 +319,36 @@ AS foo;
SET client_min_messages TO NOTICE;
-- test subquery join on VARCHAR partition column
SELECT * FROM
(SELECT
a_inner AS a
FROM
(SELECT
subquery_pruning_varchar_test_table.a AS a_inner
FROM
subquery_pruning_varchar_test_table
GROUP BY
subquery_pruning_varchar_test_table.a
HAVING
count(subquery_pruning_varchar_test_table.a) < 3)
AS f1,
(SELECT
subquery_pruning_varchar_test_table.a
FROM
subquery_pruning_varchar_test_table
GROUP BY
subquery_pruning_varchar_test_table.a
HAVING
sum(coalesce(subquery_pruning_varchar_test_table.b,0)) > 20.0)
AS f2
WHERE
f1.a_inner = f2.a
GROUP BY
a_inner)
AS foo;
DROP TABLE subquery_pruning_varchar_test_table;
ALTER SEQUENCE pg_catalog.pg_dist_shardid_seq RESTART 102026;

32
src/test/regress/output/multi_subquery.source
View File

@ -367,5 +367,37 @@ DEBUG: predicate pruning for shardId 102026
(0 rows)
SET client_min_messages TO NOTICE;
-- test subquery join on VARCHAR partition column
SELECT * FROM
(SELECT
a_inner AS a
FROM
(SELECT
subquery_pruning_varchar_test_table.a AS a_inner
FROM
subquery_pruning_varchar_test_table
GROUP BY
subquery_pruning_varchar_test_table.a
HAVING
count(subquery_pruning_varchar_test_table.a) < 3)
AS f1,
(SELECT
subquery_pruning_varchar_test_table.a
FROM
subquery_pruning_varchar_test_table
GROUP BY
subquery_pruning_varchar_test_table.a
HAVING
sum(coalesce(subquery_pruning_varchar_test_table.b,0)) > 20.0)
AS f2
WHERE
f1.a_inner = f2.a
GROUP BY
a_inner)
AS foo;
a
---
(0 rows)
DROP TABLE subquery_pruning_varchar_test_table;
ALTER SEQUENCE pg_catalog.pg_dist_shardid_seq RESTART 102026;