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ibrahim halatci (ihalatci) wants to merge 1 commit into
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Reject FOR PORTION OF distributed modifications #8763

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10 changes: 10 additions & 0 deletions src/backend/distributed/planner/multi_router_planner.c
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Original file line number Diff line number Diff line change
Expand Up @@ -742,6 +742,16 @@ static DeferredErrorMessage *
ModifyPartialQuerySupported(Query *queryTree, bool multiShardQuery,
Oid *distributedTableIdOutput)
{
#if PG_VERSION_NUM >= PG_VERSION_19
if (queryTree->forPortionOf != NULL)
{
return DeferredError(ERRCODE_FEATURE_NOT_SUPPORTED,
"Citus cannot preserve temporal leftover-row semantics "
"for FOR PORTION OF",
NULL, NULL);
}
#endif

DeferredErrorMessage *deferredError = DeferErrorIfModifyView(queryTree);
if (deferredError != NULL)
{
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105 changes: 105 additions & 0 deletions src/test/regress/expected/pg19.out
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Expand Up @@ -946,3 +946,108 @@ DROP ROLE pg19_owner, pg19_grantor_a, pg19_grantor_b, pg19_actor, pg19_grantee;
DROP ROLE "Grant Owner", pg19_grantee2;
RESET client_min_messages;
RESET search_path;
--
-- FOR PORTION OF UPDATE/DELETE creates leftover rows for the parts of a
-- temporal range outside the requested portion. PostgreSQL handles ordinary
-- local tables, but Citus must reject queries that require distributed
-- planning until it can preserve those leftover-row semantics.
--
CREATE SCHEMA pg19_for_portion_of;
SET search_path TO pg19_for_portion_of;
SET datestyle TO ISO, YMD;
SET citus.shard_count TO 4;
SET citus.shard_replication_factor TO 1;
-- Pure PostgreSQL execution remains supported, including both syntaxes.
CREATE TABLE temporal_local (id int, valid_at daterange, value text);
INSERT INTO temporal_local VALUES
(1, '[2020-01-01,2021-01-01)', 'original');
UPDATE temporal_local
FOR PORTION OF valid_at FROM '2020-03-01' TO '2020-09-01'
SET value = 'from_to'
WHERE id = 1;
UPDATE temporal_local
FOR PORTION OF valid_at (daterange('2020-05-01', '2020-07-01'))
SET value = 'direct'
WHERE id = 1;
SELECT * FROM temporal_local ORDER BY id, valid_at;
id | valid_at | value
---------------------------------------------------------------------
1 | [2020-01-01,2020-03-01) | original
1 | [2020-03-01,2020-05-01) | from_to
1 | [2020-05-01,2020-07-01) | direct
1 | [2020-07-01,2020-09-01) | from_to
1 | [2020-09-01,2021-01-01) | original
(5 rows)

CREATE TABLE temporal_dist (id int, valid_at daterange, value text);
SELECT create_distributed_table('temporal_dist', 'id');
create_distributed_table
---------------------------------------------------------------------

(1 row)

INSERT INTO temporal_dist VALUES
(1, '[2020-01-01,2021-01-01)', 'distributed');
-- Rejection does not depend on whether a local shard could execute the query.
SET citus.enable_local_execution TO ON;
UPDATE temporal_dist
FOR PORTION OF valid_at FROM '2020-03-01' TO '2020-09-01'
SET value = 'updated'
WHERE id = 1;
ERROR: Citus cannot preserve temporal leftover-row semantics for FOR PORTION OF
DELETE FROM temporal_dist
FOR PORTION OF valid_at (daterange('2020-03-01', '2020-09-01'))
WHERE id = 1;
ERROR: Citus cannot preserve temporal leftover-row semantics for FOR PORTION OF
SET citus.enable_local_execution TO OFF;
UPDATE temporal_dist
FOR PORTION OF valid_at (daterange('2020-03-01', '2020-09-01'))
SET value = 'updated'
WHERE id = 1;
ERROR: Citus cannot preserve temporal leftover-row semantics for FOR PORTION OF
DELETE FROM temporal_dist
FOR PORTION OF valid_at FROM '2020-03-01' TO '2020-09-01'
WHERE id = 1;
ERROR: Citus cannot preserve temporal leftover-row semantics for FOR PORTION OF
RESET citus.enable_local_execution;
-- The same early rejection applies when the modification is nested in a CTE.
WITH changed AS (
UPDATE temporal_dist
FOR PORTION OF valid_at FROM '2020-03-01' TO '2020-09-01'
SET value = 'updated'
WHERE id = 1
RETURNING *
)
SELECT count(*) FROM changed;
ERROR: Citus cannot preserve temporal leftover-row semantics for FOR PORTION OF
-- An ordinary local target still needs Citus planning when it reads a
-- distributed source.
CREATE TABLE temporal_local_from_dist
(id int, valid_at daterange, value text);
INSERT INTO temporal_local_from_dist VALUES
(1, '[2020-01-01,2021-01-01)', 'local');
UPDATE temporal_local_from_dist
FOR PORTION OF valid_at FROM '2020-03-01' TO '2020-09-01'
AS local_target
SET value = source.value
FROM temporal_dist AS source
WHERE local_target.id = source.id;
ERROR: Citus cannot preserve temporal leftover-row semantics for FOR PORTION OF
-- Reject even when the temporal period is also the distribution column.
CREATE TABLE temporal_period_dist (valid_at daterange, value text);
SELECT create_distributed_table('temporal_period_dist', 'valid_at');
create_distributed_table
---------------------------------------------------------------------

(1 row)

INSERT INTO temporal_period_dist VALUES
('[2020-01-01,2021-01-01)', 'distributed by period');
DELETE FROM temporal_period_dist
FOR PORTION OF valid_at FROM '2020-03-01' TO '2020-09-01';
ERROR: Citus cannot preserve temporal leftover-row semantics for FOR PORTION OF
SET client_min_messages TO WARNING;
DROP SCHEMA pg19_for_portion_of CASCADE;
RESET client_min_messages;
RESET datestyle;
RESET search_path;
91 changes: 91 additions & 0 deletions src/test/regress/sql/pg19.sql
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Original file line number Diff line number Diff line change
Expand Up @@ -711,3 +711,94 @@ DROP ROLE pg19_owner, pg19_grantor_a, pg19_grantor_b, pg19_actor, pg19_grantee;
DROP ROLE "Grant Owner", pg19_grantee2;
RESET client_min_messages;
RESET search_path;

--
-- FOR PORTION OF UPDATE/DELETE creates leftover rows for the parts of a
-- temporal range outside the requested portion. PostgreSQL handles ordinary
-- local tables, but Citus must reject queries that require distributed
-- planning until it can preserve those leftover-row semantics.
--
CREATE SCHEMA pg19_for_portion_of;
SET search_path TO pg19_for_portion_of;
SET datestyle TO ISO, YMD;
SET citus.shard_count TO 4;
SET citus.shard_replication_factor TO 1;

-- Pure PostgreSQL execution remains supported, including both syntaxes.
CREATE TABLE temporal_local (id int, valid_at daterange, value text);
INSERT INTO temporal_local VALUES
(1, '[2020-01-01,2021-01-01)', 'original');

UPDATE temporal_local
FOR PORTION OF valid_at FROM '2020-03-01' TO '2020-09-01'
SET value = 'from_to'
WHERE id = 1;

UPDATE temporal_local
FOR PORTION OF valid_at (daterange('2020-05-01', '2020-07-01'))
SET value = 'direct'
WHERE id = 1;

SELECT * FROM temporal_local ORDER BY id, valid_at;

CREATE TABLE temporal_dist (id int, valid_at daterange, value text);
SELECT create_distributed_table('temporal_dist', 'id');
INSERT INTO temporal_dist VALUES
(1, '[2020-01-01,2021-01-01)', 'distributed');

-- Rejection does not depend on whether a local shard could execute the query.
SET citus.enable_local_execution TO ON;
UPDATE temporal_dist
FOR PORTION OF valid_at FROM '2020-03-01' TO '2020-09-01'
SET value = 'updated'
WHERE id = 1;
DELETE FROM temporal_dist
FOR PORTION OF valid_at (daterange('2020-03-01', '2020-09-01'))
WHERE id = 1;

SET citus.enable_local_execution TO OFF;
UPDATE temporal_dist
FOR PORTION OF valid_at (daterange('2020-03-01', '2020-09-01'))
SET value = 'updated'
WHERE id = 1;
DELETE FROM temporal_dist
FOR PORTION OF valid_at FROM '2020-03-01' TO '2020-09-01'
WHERE id = 1;
RESET citus.enable_local_execution;

-- The same early rejection applies when the modification is nested in a CTE.
WITH changed AS (
UPDATE temporal_dist
FOR PORTION OF valid_at FROM '2020-03-01' TO '2020-09-01'
SET value = 'updated'
WHERE id = 1
RETURNING *
)
SELECT count(*) FROM changed;

-- An ordinary local target still needs Citus planning when it reads a
-- distributed source.
CREATE TABLE temporal_local_from_dist
(id int, valid_at daterange, value text);
INSERT INTO temporal_local_from_dist VALUES
(1, '[2020-01-01,2021-01-01)', 'local');
UPDATE temporal_local_from_dist
FOR PORTION OF valid_at FROM '2020-03-01' TO '2020-09-01'
AS local_target
SET value = source.value
FROM temporal_dist AS source
WHERE local_target.id = source.id;

-- Reject even when the temporal period is also the distribution column.
CREATE TABLE temporal_period_dist (valid_at daterange, value text);
SELECT create_distributed_table('temporal_period_dist', 'valid_at');
INSERT INTO temporal_period_dist VALUES
('[2020-01-01,2021-01-01)', 'distributed by period');
DELETE FROM temporal_period_dist
FOR PORTION OF valid_at FROM '2020-03-01' TO '2020-09-01';

SET client_min_messages TO WARNING;
DROP SCHEMA pg19_for_portion_of CASCADE;
RESET client_min_messages;
RESET datestyle;
RESET search_path;
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