From c52f36019fceeb8894f4c7a0e52d7225a0f78d09 Mon Sep 17 00:00:00 2001 From: Colm McHugh Date: Fri, 25 Oct 2024 11:24:01 +0000 Subject: [PATCH] [Bug Fix] [SEGFAULT] Querying distributed tables with window partition may cause segfault #7705 In function MasterAggregateMutator(), when the original Node is a Var node use makeVar() instead of copyObject() when constructing the Var node for the target list of the combine query. The varnullingrels field of the original Var node is ignored because it is not relevant for the combine query; copying this cause the problem in issue 7705, where a coordinator query had a Var with a reference to a non-existent join relation. --- .../planner/multi_logical_optimizer.c | 7 +- src/test/regress/expected/issue_7705.out | 248 ++++++++++++++++++ src/test/regress/multi_schedule | 2 +- src/test/regress/sql/issue_7705.sql | 72 +++++ 4 files changed, 325 insertions(+), 4 deletions(-) create mode 100644 src/test/regress/expected/issue_7705.out create mode 100644 src/test/regress/sql/issue_7705.sql diff --git a/src/backend/distributed/planner/multi_logical_optimizer.c b/src/backend/distributed/planner/multi_logical_optimizer.c index 371ba54e650..28680deb036 100644 --- a/src/backend/distributed/planner/multi_logical_optimizer.c +++ b/src/backend/distributed/planner/multi_logical_optimizer.c @@ -1557,9 +1557,10 @@ MasterAggregateMutator(Node *originalNode, MasterAggregateWalkerContext *walkerC } else if (IsA(originalNode, Var)) { - Var *newColumn = copyObject((Var *) originalNode); - newColumn->varno = masterTableId; - newColumn->varattno = walkerContext->columnId; + Var *origColumn = (Var *) originalNode; + Var *newColumn = makeVar(masterTableId, walkerContext->columnId, + origColumn->vartype, origColumn->vartypmod, + origColumn->varcollid, origColumn->varlevelsup); walkerContext->columnId++; newNode = (Node *) newColumn; diff --git a/src/test/regress/expected/issue_7705.out b/src/test/regress/expected/issue_7705.out new file mode 100644 index 00000000000..20b078226ad --- /dev/null +++ b/src/test/regress/expected/issue_7705.out @@ -0,0 +1,248 @@ +--- Test for verifying that column references (var nodes) in targets that cannot be pushed down +--- do not cause issues for the postgres planner, in particular postgres versions 16+, where the +--- varnullingrels field of a VAR node may contain relids of join relations that can make the var +--- NULL; in a rewritten distributed query without a join such relids do not have a meaning. +--- Issue #7705: [SEGFAULT] Querying distributed tables with window partition causes segmentation fault +--- https://github.com/citusdata/citus/issues/7705 +CREATE SCHEMA issue_7705; +SET search_path to 'issue_7705'; +SET citus.next_shard_id TO 30070000; +SET citus.shard_replication_factor TO 1; +SET citus.enable_local_execution TO ON; +CREATE TABLE t1 (id INT PRIMARY KEY); +INSERT INTO t1 VALUES (1), (2); +CREATE TABLE t2 (id INT, account_id INT, a2 INT, PRIMARY KEY(id, account_id)); +INSERT INTO t2 VALUES (3, 1, 10), (4, 2, 20), (5, 1, NULL); +SELECT create_distributed_table('t1', 'id'); +NOTICE: Copying data from local table... +NOTICE: copying the data has completed +DETAIL: The local data in the table is no longer visible, but is still on disk. +HINT: To remove the local data, run: SELECT truncate_local_data_after_distributing_table($$issue_7705.t1$$) + create_distributed_table +--------------------------------------------------------------------- + +(1 row) + +SELECT create_distributed_table('t2', 'account_id'); +NOTICE: Copying data from local table... +NOTICE: copying the data has completed +DETAIL: The local data in the table is no longer visible, but is still on disk. +HINT: To remove the local data, run: SELECT truncate_local_data_after_distributing_table($$issue_7705.t2$$) + create_distributed_table +--------------------------------------------------------------------- + +(1 row) + +-- Test the issue seen in #7705; a target expression with +-- a window function that cannot be pushed down because the +-- partion by is not on the distribution column also includes +-- a column from the inner side of a left outer join, which +-- produces a non-empty varnullingrels set in PG 16 (and higher) +SELECT t1.id, MAX(t2.a2) OVER (PARTITION BY t2.id) +FROM t1 LEFT OUTER JOIN t2 ON t1.id = t2.account_id; + id | max +--------------------------------------------------------------------- + 1 | 10 + 2 | 20 + 1 | +(3 rows) + +EXPLAIN (VERBOSE, COSTS OFF, TIMING OFF) +SELECT t1.id, MAX(t2.a2) OVER (PARTITION BY t2.id) +FROM t1 LEFT OUTER JOIN t2 ON t1.id = t2.account_id; + QUERY PLAN +--------------------------------------------------------------------- + WindowAgg + Output: remote_scan.id, max(remote_scan.max) OVER (?), remote_scan.worker_column_3 + -> Sort + Output: remote_scan.worker_column_3, remote_scan.id, remote_scan.max + Sort Key: remote_scan.worker_column_3 + -> Custom Scan (Citus Adaptive) + Output: remote_scan.worker_column_3, remote_scan.id, remote_scan.max + Task Count: 4 + Tasks Shown: One of 4 + -> Task + Query: SELECT worker_column_1 AS id, worker_column_2 AS max, worker_column_3 FROM (SELECT t1.id AS worker_column_1, t2.a2 AS worker_column_2, t2.id AS worker_column_3 FROM (issue_7705.t1_30070000 t1 LEFT JOIN issue_7705.t2_30070004 t2 ON ((t1.id OPERATOR(pg_catalog.=) t2.account_id)))) worker_subquery + Node: host=localhost port=xxxxx dbname=regression + -> Hash Right Join + Output: t1.id, t2.a2, t2.id + Inner Unique: true + Hash Cond: (t2.account_id = t1.id) + -> Seq Scan on issue_7705.t2_30070004 t2 + Output: t2.id, t2.account_id, t2.a2 + -> Hash + Output: t1.id + -> Seq Scan on issue_7705.t1_30070000 t1 + Output: t1.id +(22 rows) + +SELECT t1.id, MAX(t2.a2) OVER (PARTITION BY t2.id) +FROM t2 RIGHT OUTER JOIN t1 ON t1.id = t2.account_id; + id | max +--------------------------------------------------------------------- + 1 | 10 + 2 | 20 + 1 | +(3 rows) + +EXPLAIN (VERBOSE, COSTS OFF, TIMING OFF) +SELECT t1.id, MAX(t2.a2) OVER (PARTITION BY t2.id) +FROM t2 RIGHT OUTER JOIN t1 ON t1.id = t2.account_id; + QUERY PLAN +--------------------------------------------------------------------- + WindowAgg + Output: remote_scan.id, max(remote_scan.max) OVER (?), remote_scan.worker_column_3 + -> Sort + Output: remote_scan.worker_column_3, remote_scan.id, remote_scan.max + Sort Key: remote_scan.worker_column_3 + -> Custom Scan (Citus Adaptive) + Output: remote_scan.worker_column_3, remote_scan.id, remote_scan.max + Task Count: 4 + Tasks Shown: One of 4 + -> Task + Query: SELECT worker_column_1 AS id, worker_column_2 AS max, worker_column_3 FROM (SELECT t1.id AS worker_column_1, t2.a2 AS worker_column_2, t2.id AS worker_column_3 FROM (issue_7705.t2_30070004 t2 RIGHT JOIN issue_7705.t1_30070000 t1 ON ((t1.id OPERATOR(pg_catalog.=) t2.account_id)))) worker_subquery + Node: host=localhost port=xxxxx dbname=regression + -> Hash Right Join + Output: t1.id, t2.a2, t2.id + Inner Unique: true + Hash Cond: (t2.account_id = t1.id) + -> Seq Scan on issue_7705.t2_30070004 t2 + Output: t2.id, t2.account_id, t2.a2 + -> Hash + Output: t1.id + -> Seq Scan on issue_7705.t1_30070000 t1 + Output: t1.id +(22 rows) + +SELECT DISTINCT t1.id, MAX(t2.a2) OVER (PARTITION BY t2.id) +FROM t1 LEFT OUTER JOIN t2 ON t1.id = t2.account_id; + id | max +--------------------------------------------------------------------- + 1 | + 1 | 10 + 2 | 20 +(3 rows) + +EXPLAIN (VERBOSE, COSTS OFF, TIMING OFF) +SELECT DISTINCT t1.id, MAX(t2.a2) OVER (PARTITION BY t2.id) +FROM t1 LEFT OUTER JOIN t2 ON t1.id = t2.account_id; + QUERY PLAN +--------------------------------------------------------------------- + HashAggregate + Output: remote_scan.id, (max(remote_scan.max) OVER (?)), remote_scan.worker_column_3 + Group Key: remote_scan.id, max(remote_scan.max) OVER (?) + -> WindowAgg + Output: remote_scan.id, max(remote_scan.max) OVER (?), remote_scan.worker_column_3 + -> Sort + Output: remote_scan.worker_column_3, remote_scan.id, remote_scan.max + Sort Key: remote_scan.worker_column_3 + -> Custom Scan (Citus Adaptive) + Output: remote_scan.worker_column_3, remote_scan.id, remote_scan.max + Task Count: 4 + Tasks Shown: One of 4 + -> Task + Query: SELECT worker_column_1 AS id, worker_column_2 AS max, worker_column_3 FROM (SELECT t1.id AS worker_column_1, t2.a2 AS worker_column_2, t2.id AS worker_column_3 FROM (issue_7705.t1_30070000 t1 LEFT JOIN issue_7705.t2_30070004 t2 ON ((t1.id OPERATOR(pg_catalog.=) t2.account_id)))) worker_subquery + Node: host=localhost port=xxxxx dbname=regression + -> Hash Right Join + Output: t1.id, t2.a2, t2.id + Inner Unique: true + Hash Cond: (t2.account_id = t1.id) + -> Seq Scan on issue_7705.t2_30070004 t2 + Output: t2.id, t2.account_id, t2.a2 + -> Hash + Output: t1.id + -> Seq Scan on issue_7705.t1_30070000 t1 + Output: t1.id +(25 rows) + +CREATE SEQUENCE test_seq START 101; +CREATE OR REPLACE FUNCTION TEST_F(int) returns INT language sql stable as $$ select $1 + 42; $$ ; +-- Issue #7705 also occurs if a target expression includes a column +-- of a distributed table that is on the inner side of a left outer +-- join and a call to nextval(), because nextval() cannot be pushed +-- down, and must be run on the coordinator +SELECT t1.id, TEST_F(t2.a2 + nextval('test_seq') :: int) +FROM t1 LEFT OUTER JOIN t2 ON t1.id = t2.account_id +ORDER BY t1.id; + id | test_f +--------------------------------------------------------------------- + 1 | 153 + 1 | + 2 | 165 +(3 rows) + +EXPLAIN (VERBOSE, COSTS OFF, TIMING OFF) +SELECT t1.id, TEST_F(t2.a2 + nextval('test_seq') :: int) +FROM t1 LEFT OUTER JOIN t2 ON t1.id = t2.account_id +ORDER BY t1.id; + QUERY PLAN +--------------------------------------------------------------------- + Result + Output: remote_scan.id, ((remote_scan.test_f + (nextval('test_seq'::regclass))::integer) + 42) + -> Sort + Output: remote_scan.id, remote_scan.test_f + Sort Key: remote_scan.id + -> Custom Scan (Citus Adaptive) + Output: remote_scan.id, remote_scan.test_f + Task Count: 4 + Tasks Shown: One of 4 + -> Task + Query: SELECT worker_column_1 AS id, worker_column_2 AS test_f FROM (SELECT t1.id AS worker_column_1, t2.a2 AS worker_column_2 FROM (issue_7705.t1_30070000 t1 LEFT JOIN issue_7705.t2_30070004 t2 ON ((t1.id OPERATOR(pg_catalog.=) t2.account_id)))) worker_subquery + Node: host=localhost port=xxxxx dbname=regression + -> Hash Right Join + Output: t1.id, t2.a2 + Inner Unique: true + Hash Cond: (t2.account_id = t1.id) + -> Seq Scan on issue_7705.t2_30070004 t2 + Output: t2.id, t2.account_id, t2.a2 + -> Hash + Output: t1.id + -> Seq Scan on issue_7705.t1_30070000 t1 + Output: t1.id +(22 rows) + +SELECT t1.id, CASE nextval('test_seq') % 2 = 0 WHEN true THEN t2.a2 ELSE 1 END +FROM t1 LEFT OUTER JOIN t2 ON t1.id = t2.account_id +ORDER BY t1.id; + id | case +--------------------------------------------------------------------- + 1 | 10 + 1 | 1 + 2 | 20 +(3 rows) + +EXPLAIN (VERBOSE, COSTS OFF, TIMING OFF) +SELECT t1.id, CASE nextval('test_seq') %2 = 0 WHEN true THEN t2.a2 ELSE 1 END +FROM t1 LEFT OUTER JOIN t2 ON t1.id = t2.account_id +ORDER BY t1.id; + QUERY PLAN +--------------------------------------------------------------------- + Result + Output: remote_scan.id, CASE ((nextval('test_seq'::regclass) % '2'::bigint) = 0) WHEN CASE_TEST_EXPR THEN remote_scan."case" ELSE 1 END + -> Sort + Output: remote_scan.id, remote_scan."case" + Sort Key: remote_scan.id + -> Custom Scan (Citus Adaptive) + Output: remote_scan.id, remote_scan."case" + Task Count: 4 + Tasks Shown: One of 4 + -> Task + Query: SELECT worker_column_1 AS id, worker_column_2 AS "case" FROM (SELECT t1.id AS worker_column_1, t2.a2 AS worker_column_2 FROM (issue_7705.t1_30070000 t1 LEFT JOIN issue_7705.t2_30070004 t2 ON ((t1.id OPERATOR(pg_catalog.=) t2.account_id)))) worker_subquery + Node: host=localhost port=xxxxx dbname=regression + -> Hash Right Join + Output: t1.id, t2.a2 + Inner Unique: true + Hash Cond: (t2.account_id = t1.id) + -> Seq Scan on issue_7705.t2_30070004 t2 + Output: t2.id, t2.account_id, t2.a2 + -> Hash + Output: t1.id + -> Seq Scan on issue_7705.t1_30070000 t1 + Output: t1.id +(22 rows) + +--- cleanup +\set VERBOSITY TERSE +DROP SCHEMA issue_7705 CASCADE; +NOTICE: drop cascades to 4 other objects +RESET all; diff --git a/src/test/regress/multi_schedule b/src/test/regress/multi_schedule index 220ce1964f1..bbb4047a950 100644 --- a/src/test/regress/multi_schedule +++ b/src/test/regress/multi_schedule @@ -103,7 +103,7 @@ test: multi_dropped_column_aliases foreign_key_restriction_enforcement test: binary_protocol test: alter_table_set_access_method test: alter_distributed_table -test: issue_5248 issue_5099 issue_5763 issue_6543 issue_6758 issue_7477 +test: issue_5248 issue_5099 issue_5763 issue_6543 issue_6758 issue_7477 issue_7705 test: object_propagation_debug test: undistribute_table test: run_command_on_all_nodes diff --git a/src/test/regress/sql/issue_7705.sql b/src/test/regress/sql/issue_7705.sql new file mode 100644 index 00000000000..950933017ad --- /dev/null +++ b/src/test/regress/sql/issue_7705.sql @@ -0,0 +1,72 @@ +--- Test for verifying that column references (var nodes) in targets that cannot be pushed down +--- do not cause issues for the postgres planner, in particular postgres versions 16+, where the +--- varnullingrels field of a VAR node may contain relids of join relations that can make the var +--- NULL; in a rewritten distributed query without a join such relids do not have a meaning. +--- Issue #7705: [SEGFAULT] Querying distributed tables with window partition causes segmentation fault +--- https://github.com/citusdata/citus/issues/7705 + +CREATE SCHEMA issue_7705; +SET search_path to 'issue_7705'; +SET citus.next_shard_id TO 30070000; +SET citus.shard_replication_factor TO 1; +SET citus.enable_local_execution TO ON; + +CREATE TABLE t1 (id INT PRIMARY KEY); +INSERT INTO t1 VALUES (1), (2); + +CREATE TABLE t2 (id INT, account_id INT, a2 INT, PRIMARY KEY(id, account_id)); +INSERT INTO t2 VALUES (3, 1, 10), (4, 2, 20), (5, 1, NULL); + +SELECT create_distributed_table('t1', 'id'); +SELECT create_distributed_table('t2', 'account_id'); + +-- Test the issue seen in #7705; a target expression with +-- a window function that cannot be pushed down because the +-- partion by is not on the distribution column also includes +-- a column from the inner side of a left outer join, which +-- produces a non-empty varnullingrels set in PG 16 (and higher) +SELECT t1.id, MAX(t2.a2) OVER (PARTITION BY t2.id) +FROM t1 LEFT OUTER JOIN t2 ON t1.id = t2.account_id; +EXPLAIN (VERBOSE, COSTS OFF, TIMING OFF) +SELECT t1.id, MAX(t2.a2) OVER (PARTITION BY t2.id) +FROM t1 LEFT OUTER JOIN t2 ON t1.id = t2.account_id; + +SELECT t1.id, MAX(t2.a2) OVER (PARTITION BY t2.id) +FROM t2 RIGHT OUTER JOIN t1 ON t1.id = t2.account_id; +EXPLAIN (VERBOSE, COSTS OFF, TIMING OFF) +SELECT t1.id, MAX(t2.a2) OVER (PARTITION BY t2.id) +FROM t2 RIGHT OUTER JOIN t1 ON t1.id = t2.account_id; + +SELECT DISTINCT t1.id, MAX(t2.a2) OVER (PARTITION BY t2.id) +FROM t1 LEFT OUTER JOIN t2 ON t1.id = t2.account_id; +EXPLAIN (VERBOSE, COSTS OFF, TIMING OFF) +SELECT DISTINCT t1.id, MAX(t2.a2) OVER (PARTITION BY t2.id) +FROM t1 LEFT OUTER JOIN t2 ON t1.id = t2.account_id; + +CREATE SEQUENCE test_seq START 101; +CREATE OR REPLACE FUNCTION TEST_F(int) returns INT language sql stable as $$ select $1 + 42; $$ ; + +-- Issue #7705 also occurs if a target expression includes a column +-- of a distributed table that is on the inner side of a left outer +-- join and a call to nextval(), because nextval() cannot be pushed +-- down, and must be run on the coordinator +SELECT t1.id, TEST_F(t2.a2 + nextval('test_seq') :: int) +FROM t1 LEFT OUTER JOIN t2 ON t1.id = t2.account_id +ORDER BY t1.id; +EXPLAIN (VERBOSE, COSTS OFF, TIMING OFF) +SELECT t1.id, TEST_F(t2.a2 + nextval('test_seq') :: int) +FROM t1 LEFT OUTER JOIN t2 ON t1.id = t2.account_id +ORDER BY t1.id; + +SELECT t1.id, CASE nextval('test_seq') % 2 = 0 WHEN true THEN t2.a2 ELSE 1 END +FROM t1 LEFT OUTER JOIN t2 ON t1.id = t2.account_id +ORDER BY t1.id; +EXPLAIN (VERBOSE, COSTS OFF, TIMING OFF) +SELECT t1.id, CASE nextval('test_seq') %2 = 0 WHEN true THEN t2.a2 ELSE 1 END +FROM t1 LEFT OUTER JOIN t2 ON t1.id = t2.account_id +ORDER BY t1.id; + +--- cleanup +\set VERBOSITY TERSE +DROP SCHEMA issue_7705 CASCADE; +RESET all;