From: Alvaro Herrera <alvherre@alvh.no-ip.org>
Date: Wed, 9 May 2018 13:51:23 +0000 (-0300)
Subject: Fix assorted partition pruning bugs
X-Git-Tag: REL_11_BETA1~62
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=d758d9702e2f64f08565e18eb6cb7991efa2dc16;p=postgresql
Fix assorted partition pruning bugs
match_clause_to_partition_key failed to consider COERCION_PATH_ARRAYCOERCE
cases in scalar-op-array expressions, so it was possible to crash the
server easily. To handle this case properly (ie. prune partitions) we
would need to run a bit of executor code during planning. Maybe it can
be improved, but for now let's just not crash. Add a test case that
used to trigger the crash.
Author: Michaël Paquier
match_clause_to_partition_key failed to indicate that operators that
don't have a commutator in a btree opclass are unsupported. It is
possible for this to cause a crash later if such an operator is used in
a scalar-op-array expression. Add a test case that used to the crash.
Author: Amit Langote
One caller of gen_partprune_steps_internal in
match_clause_to_partition_key was too optimistic about the former never
returning an empty step list. Rid it of its innocence. (Having fixed
the bug above, I no longer know how to exploit this, so no test case for
it, but it remained a bug.) Revise code flow a little bit, for
succintness.
Author: Álvaro Herrera
Reported-by: Marina Polyakova
Reviewed-by: Michaël Paquier
Reviewed-by: Amit Langote
Reviewed-by: Álvaro Herrera
Discussion: https://postgr.es/m/ff8f9bfa485ff961d6bb43e54120485b@postgrespro.ru
---
diff --git a/src/backend/partitioning/partprune.c b/src/backend/partitioning/partprune.c
index 69879bf3a4..58ec2a684d 100644
--- a/src/backend/partitioning/partprune.c
+++ b/src/backend/partitioning/partprune.c
@@ -573,8 +573,9 @@ get_matching_partitions(PartitionPruneContext *context, List *pruning_steps)
* For BoolExpr clauses, we recursively generate steps for each argument, and
* return a PartitionPruneStepCombine of their results.
*
- * The generated steps are added to the context's steps list. Each step is
- * assigned a step identifier, unique even across recursive calls.
+ * The return value is a list of the steps generated, which are also added to
+ * the context's steps list. Each step is assigned a step identifier, unique
+ * even across recursive calls.
*
* If we find clauses that are mutually contradictory, or a pseudoconstant
* clause that contains false, we set *contradictory to true and return NIL
@@ -1601,6 +1602,7 @@ match_clause_to_partition_key(RelOptInfo *rel,
List *elem_exprs,
*elem_clauses;
ListCell *lc1;
+ bool contradictory;
if (IsA(leftop, RelabelType))
leftop = ((RelabelType *) leftop)->arg;
@@ -1619,7 +1621,7 @@ match_clause_to_partition_key(RelOptInfo *rel,
* Only allow strict operators. This will guarantee nulls are
* filtered.
*/
- if (!op_strict(saop->opno))
+ if (!op_strict(saop_op))
return PARTCLAUSE_UNSUPPORTED;
/* Useless if the array has any volatile functions. */
@@ -1652,6 +1654,8 @@ match_clause_to_partition_key(RelOptInfo *rel,
if (strategy != BTEqualStrategyNumber)
return PARTCLAUSE_UNSUPPORTED;
}
+ else
+ return PARTCLAUSE_UNSUPPORTED; /* no useful negator */
}
/*
@@ -1692,7 +1696,7 @@ match_clause_to_partition_key(RelOptInfo *rel,
elem_exprs = lappend(elem_exprs, elem_expr);
}
}
- else
+ else if (IsA(rightop, ArrayExpr))
{
ArrayExpr *arrexpr = castNode(ArrayExpr, rightop);
@@ -1706,6 +1710,11 @@ match_clause_to_partition_key(RelOptInfo *rel,
elem_exprs = arrexpr->elements;
}
+ else
+ {
+ /* Give up on any other clause types. */
+ return PARTCLAUSE_UNSUPPORTED;
+ }
/*
* Now generate a list of clauses, one for each array element, of the
@@ -1724,36 +1733,21 @@ match_clause_to_partition_key(RelOptInfo *rel,
}
/*
- * Build a combine step as if for an OR clause or add the clauses to
- * the end of the list that's being processed currently.
+ * If we have an ANY clause and multiple elements, first turn the list
+ * of clauses into an OR expression.
*/
if (saop->useOr && list_length(elem_clauses) > 1)
- {
- Expr *orexpr;
- bool contradictory;
-
- orexpr = makeBoolExpr(OR_EXPR, elem_clauses, -1);
- *clause_steps =
- gen_partprune_steps_internal(context, rel, list_make1(orexpr),
- &contradictory);
- if (contradictory)
- return PARTCLAUSE_MATCH_CONTRADICT;
-
- Assert(list_length(*clause_steps) == 1);
- return PARTCLAUSE_MATCH_STEPS;
- }
- else
- {
- bool contradictory;
-
- *clause_steps =
- gen_partprune_steps_internal(context, rel, elem_clauses,
- &contradictory);
- if (contradictory)
- return PARTCLAUSE_MATCH_CONTRADICT;
- Assert(list_length(*clause_steps) >= 1);
- return PARTCLAUSE_MATCH_STEPS;
- }
+ elem_clauses = list_make1(makeBoolExpr(OR_EXPR, elem_clauses, -1));
+
+ /* Finally, generate steps */
+ *clause_steps =
+ gen_partprune_steps_internal(context, rel, elem_clauses,
+ &contradictory);
+ if (contradictory)
+ return PARTCLAUSE_MATCH_CONTRADICT;
+ else if (*clause_steps == NIL)
+ return PARTCLAUSE_UNSUPPORTED; /* step generation failed */
+ return PARTCLAUSE_MATCH_STEPS;
}
else if (IsA(clause, NullTest))
{
diff --git a/src/test/regress/expected/partition_prune.out b/src/test/regress/expected/partition_prune.out
index e0cc5f3393..cf331e79c1 100644
--- a/src/test/regress/expected/partition_prune.out
+++ b/src/test/regress/expected/partition_prune.out
@@ -1073,6 +1073,72 @@ explain (costs off) select * from boolpart where a is not unknown;
Filter: (a IS NOT UNKNOWN)
(7 rows)
+-- test scalar-to-array operators
+create table coercepart (a varchar) partition by list (a);
+create table coercepart_ab partition of coercepart for values in ('ab');
+create table coercepart_bc partition of coercepart for values in ('bc');
+create table coercepart_cd partition of coercepart for values in ('cd');
+explain (costs off) select * from coercepart where a in ('ab', to_char(125, '999'));
+ QUERY PLAN
+------------------------------------------------------------------------------------------------------------------------------
+ Append
+ -> Seq Scan on coercepart_ab
+ Filter: ((a)::text = ANY ((ARRAY['ab'::character varying, (to_char(125, '999'::text))::character varying])::text[]))
+ -> Seq Scan on coercepart_bc
+ Filter: ((a)::text = ANY ((ARRAY['ab'::character varying, (to_char(125, '999'::text))::character varying])::text[]))
+ -> Seq Scan on coercepart_cd
+ Filter: ((a)::text = ANY ((ARRAY['ab'::character varying, (to_char(125, '999'::text))::character varying])::text[]))
+(7 rows)
+
+explain (costs off) select * from coercepart where a ~ any ('{ab}');
+ QUERY PLAN
+----------------------------------------------------
+ Append
+ -> Seq Scan on coercepart_ab
+ Filter: ((a)::text ~ ANY ('{ab}'::text[]))
+ -> Seq Scan on coercepart_bc
+ Filter: ((a)::text ~ ANY ('{ab}'::text[]))
+ -> Seq Scan on coercepart_cd
+ Filter: ((a)::text ~ ANY ('{ab}'::text[]))
+(7 rows)
+
+explain (costs off) select * from coercepart where a !~ all ('{ab}');
+ QUERY PLAN
+-----------------------------------------------------
+ Append
+ -> Seq Scan on coercepart_ab
+ Filter: ((a)::text !~ ALL ('{ab}'::text[]))
+ -> Seq Scan on coercepart_bc
+ Filter: ((a)::text !~ ALL ('{ab}'::text[]))
+ -> Seq Scan on coercepart_cd
+ Filter: ((a)::text !~ ALL ('{ab}'::text[]))
+(7 rows)
+
+explain (costs off) select * from coercepart where a ~ any ('{ab,bc}');
+ QUERY PLAN
+-------------------------------------------------------
+ Append
+ -> Seq Scan on coercepart_ab
+ Filter: ((a)::text ~ ANY ('{ab,bc}'::text[]))
+ -> Seq Scan on coercepart_bc
+ Filter: ((a)::text ~ ANY ('{ab,bc}'::text[]))
+ -> Seq Scan on coercepart_cd
+ Filter: ((a)::text ~ ANY ('{ab,bc}'::text[]))
+(7 rows)
+
+explain (costs off) select * from coercepart where a !~ all ('{ab,bc}');
+ QUERY PLAN
+--------------------------------------------------------
+ Append
+ -> Seq Scan on coercepart_ab
+ Filter: ((a)::text !~ ALL ('{ab,bc}'::text[]))
+ -> Seq Scan on coercepart_bc
+ Filter: ((a)::text !~ ALL ('{ab,bc}'::text[]))
+ -> Seq Scan on coercepart_cd
+ Filter: ((a)::text !~ ALL ('{ab,bc}'::text[]))
+(7 rows)
+
+drop table coercepart;
--
-- some more cases
--
diff --git a/src/test/regress/sql/partition_prune.sql b/src/test/regress/sql/partition_prune.sql
index 6b7f57ab41..1464f4dcd9 100644
--- a/src/test/regress/sql/partition_prune.sql
+++ b/src/test/regress/sql/partition_prune.sql
@@ -152,6 +152,20 @@ explain (costs off) select * from boolpart where a is not true and a is not fals
explain (costs off) select * from boolpart where a is unknown;
explain (costs off) select * from boolpart where a is not unknown;
+-- test scalar-to-array operators
+create table coercepart (a varchar) partition by list (a);
+create table coercepart_ab partition of coercepart for values in ('ab');
+create table coercepart_bc partition of coercepart for values in ('bc');
+create table coercepart_cd partition of coercepart for values in ('cd');
+
+explain (costs off) select * from coercepart where a in ('ab', to_char(125, '999'));
+explain (costs off) select * from coercepart where a ~ any ('{ab}');
+explain (costs off) select * from coercepart where a !~ all ('{ab}');
+explain (costs off) select * from coercepart where a ~ any ('{ab,bc}');
+explain (costs off) select * from coercepart where a !~ all ('{ab,bc}');
+
+drop table coercepart;
+
--
-- some more cases
--