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Etsuro Fujita
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Fix handling of pending inserts in nodeModifyTable.c.
Commit b663a41, which allowed FDWs to INSERT rows in bulk, added to nodeModifyTable.c code to flush pending inserts to the foreign-table result relation(s) before completing processing of the ModifyTable node, but the code failed to take into account the case where the INSERT query has modifying CTEs, leading to incorrect results. Also, that commit failed to flush pending inserts before firing BEFORE ROW triggers so that rows are visible to such triggers. In that commit we scanned through EState's es_tuple_routing_result_relations or es_opened_result_relations list to find the foreign-table result relations to which pending inserts are flushed, but that would be inefficient in some cases. So to fix, 1) add a List member to EState to record the insert-pending result relations, and 2) modify nodeModifyTable.c so that it adds the foreign-table result relation to the list in ExecInsert() if appropriate, and flushes pending inserts properly using the list where needed. While here, fix a copy-and-pasteo in a comment in ExecBatchInsert(), which was added by that commit. Back-patch to v14 where that commit appeared. Discussion: https://postgr.es/m/CAPmGK16qutyCmyJJzgQOhfBq%3DNoGDqTB6O0QBZTihrbqre%2BoxA%40mail.gmail.com
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‎contrib/postgres_fdw/expected/postgres_fdw.out

Lines changed: 123 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -10168,7 +10168,130 @@ SELECT * FROM batch_table ORDER BY x;
1016810168
50 | test50 | test50
1016910169
(50 rows)
1017010170

10171+
-- Clean up
10172+
DROP TABLE batch_table;
10173+
DROP TABLE batch_table_p0;
10174+
DROP TABLE batch_table_p1;
1017110175
ALTER SERVER loopback OPTIONS (DROP batch_size);
10176+
-- Test that pending inserts are handled properly when needed
10177+
CREATE TABLE batch_table (a text, b int);
10178+
CREATE FOREIGN TABLE ftable (a text, b int)
10179+
SERVER loopback
10180+
OPTIONS (table_name 'batch_table', batch_size '2');
10181+
CREATE TABLE ltable (a text, b int);
10182+
CREATE FUNCTION ftable_rowcount_trigf() RETURNS trigger LANGUAGE plpgsql AS
10183+
$$
10184+
begin
10185+
raise notice '%: there are % rows in ftable',
10186+
TG_NAME, (SELECT count(*) FROM ftable);
10187+
if TG_OP = 'DELETE' then
10188+
return OLD;
10189+
else
10190+
return NEW;
10191+
end if;
10192+
end;
10193+
$$;
10194+
CREATE TRIGGER ftable_rowcount_trigger
10195+
BEFORE INSERT OR UPDATE OR DELETE ON ltable
10196+
FOR EACH ROW EXECUTE PROCEDURE ftable_rowcount_trigf();
10197+
WITH t AS (
10198+
INSERT INTO ltable VALUES ('AAA', 42), ('BBB', 42) RETURNING *
10199+
)
10200+
INSERT INTO ftable SELECT * FROM t;
10201+
NOTICE: ftable_rowcount_trigger: there are 0 rows in ftable
10202+
NOTICE: ftable_rowcount_trigger: there are 1 rows in ftable
10203+
SELECT * FROM ltable;
10204+
a | b
10205+
-----+----
10206+
AAA | 42
10207+
BBB | 42
10208+
(2 rows)
10209+
10210+
SELECT * FROM ftable;
10211+
a | b
10212+
-----+----
10213+
AAA | 42
10214+
BBB | 42
10215+
(2 rows)
10216+
10217+
DELETE FROM ftable;
10218+
WITH t AS (
10219+
UPDATE ltable SET b = b + 100 RETURNING *
10220+
)
10221+
INSERT INTO ftable SELECT * FROM t;
10222+
NOTICE: ftable_rowcount_trigger: there are 0 rows in ftable
10223+
NOTICE: ftable_rowcount_trigger: there are 1 rows in ftable
10224+
SELECT * FROM ltable;
10225+
a | b
10226+
-----+-----
10227+
AAA | 142
10228+
BBB | 142
10229+
(2 rows)
10230+
10231+
SELECT * FROM ftable;
10232+
a | b
10233+
-----+-----
10234+
AAA | 142
10235+
BBB | 142
10236+
(2 rows)
10237+
10238+
DELETE FROM ftable;
10239+
WITH t AS (
10240+
DELETE FROM ltable RETURNING *
10241+
)
10242+
INSERT INTO ftable SELECT * FROM t;
10243+
NOTICE: ftable_rowcount_trigger: there are 0 rows in ftable
10244+
NOTICE: ftable_rowcount_trigger: there are 1 rows in ftable
10245+
SELECT * FROM ltable;
10246+
a | b
10247+
---+---
10248+
(0 rows)
10249+
10250+
SELECT * FROM ftable;
10251+
a | b
10252+
-----+-----
10253+
AAA | 142
10254+
BBB | 142
10255+
(2 rows)
10256+
10257+
DELETE FROM ftable;
10258+
-- Clean up
10259+
DROP FOREIGN TABLE ftable;
10260+
DROP TABLE batch_table;
10261+
DROP TRIGGER ftable_rowcount_trigger ON ltable;
10262+
DROP TABLE ltable;
10263+
CREATE TABLE parent (a text, b int) PARTITION BY LIST (a);
10264+
CREATE TABLE batch_table (a text, b int);
10265+
CREATE FOREIGN TABLE ftable
10266+
PARTITION OF parent
10267+
FOR VALUES IN ('AAA')
10268+
SERVER loopback
10269+
OPTIONS (table_name 'batch_table', batch_size '2');
10270+
CREATE TABLE ltable
10271+
PARTITION OF parent
10272+
FOR VALUES IN ('BBB');
10273+
CREATE TRIGGER ftable_rowcount_trigger
10274+
BEFORE INSERT ON ltable
10275+
FOR EACH ROW EXECUTE PROCEDURE ftable_rowcount_trigf();
10276+
INSERT INTO parent VALUES ('AAA', 42), ('BBB', 42), ('AAA', 42), ('BBB', 42);
10277+
NOTICE: ftable_rowcount_trigger: there are 1 rows in ftable
10278+
NOTICE: ftable_rowcount_trigger: there are 2 rows in ftable
10279+
SELECT tableoid::regclass, * FROM parent;
10280+
tableoid | a | b
10281+
----------+-----+----
10282+
ftable | AAA | 42
10283+
ftable | AAA | 42
10284+
ltable | BBB | 42
10285+
ltable | BBB | 42
10286+
(4 rows)
10287+
10288+
-- Clean up
10289+
DROP FOREIGN TABLE ftable;
10290+
DROP TABLE batch_table;
10291+
DROP TRIGGER ftable_rowcount_trigger ON ltable;
10292+
DROP TABLE ltable;
10293+
DROP TABLE parent;
10294+
DROP FUNCTION ftable_rowcount_trigf;
1017210295
-- ===================================================================
1017310296
-- test asynchronous execution
1017410297
-- ===================================================================

‎contrib/postgres_fdw/sql/postgres_fdw.sql

Lines changed: 86 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -3205,8 +3205,94 @@ INSERT INTO batch_table SELECT i, 'test'||i, 'test'|| i FROM generate_series(1,
32053205
SELECT COUNT(*) FROM batch_table;
32063206
SELECT * FROM batch_table ORDER BY x;
32073207

3208+
-- Clean up
3209+
DROP TABLE batch_table;
3210+
DROP TABLE batch_table_p0;
3211+
DROP TABLE batch_table_p1;
3212+
32083213
ALTER SERVER loopback OPTIONS (DROP batch_size);
32093214

3215+
-- Test that pending inserts are handled properly when needed
3216+
CREATE TABLE batch_table (a text, b int);
3217+
CREATE FOREIGN TABLE ftable (a text, b int)
3218+
SERVER loopback
3219+
OPTIONS (table_name 'batch_table', batch_size '2');
3220+
CREATE TABLE ltable (a text, b int);
3221+
CREATE FUNCTION ftable_rowcount_trigf() RETURNS trigger LANGUAGE plpgsql AS
3222+
$$
3223+
begin
3224+
raise notice '%: there are % rows in ftable',
3225+
TG_NAME, (SELECT count(*) FROM ftable);
3226+
if TG_OP = 'DELETE' then
3227+
return OLD;
3228+
else
3229+
return NEW;
3230+
end if;
3231+
end;
3232+
$$;
3233+
CREATE TRIGGER ftable_rowcount_trigger
3234+
BEFORE INSERT OR UPDATE OR DELETE ON ltable
3235+
FOR EACH ROW EXECUTE PROCEDURE ftable_rowcount_trigf();
3236+
3237+
WITH t AS (
3238+
INSERT INTO ltable VALUES ('AAA', 42), ('BBB', 42) RETURNING *
3239+
)
3240+
INSERT INTO ftable SELECT * FROM t;
3241+
3242+
SELECT * FROM ltable;
3243+
SELECT * FROM ftable;
3244+
DELETE FROM ftable;
3245+
3246+
WITH t AS (
3247+
UPDATE ltable SET b = b + 100 RETURNING *
3248+
)
3249+
INSERT INTO ftable SELECT * FROM t;
3250+
3251+
SELECT * FROM ltable;
3252+
SELECT * FROM ftable;
3253+
DELETE FROM ftable;
3254+
3255+
WITH t AS (
3256+
DELETE FROM ltable RETURNING *
3257+
)
3258+
INSERT INTO ftable SELECT * FROM t;
3259+
3260+
SELECT * FROM ltable;
3261+
SELECT * FROM ftable;
3262+
DELETE FROM ftable;
3263+
3264+
-- Clean up
3265+
DROP FOREIGN TABLE ftable;
3266+
DROP TABLE batch_table;
3267+
DROP TRIGGER ftable_rowcount_trigger ON ltable;
3268+
DROP TABLE ltable;
3269+
3270+
CREATE TABLE parent (a text, b int) PARTITION BY LIST (a);
3271+
CREATE TABLE batch_table (a text, b int);
3272+
CREATE FOREIGN TABLE ftable
3273+
PARTITION OF parent
3274+
FOR VALUES IN ('AAA')
3275+
SERVER loopback
3276+
OPTIONS (table_name 'batch_table', batch_size '2');
3277+
CREATE TABLE ltable
3278+
PARTITION OF parent
3279+
FOR VALUES IN ('BBB');
3280+
CREATE TRIGGER ftable_rowcount_trigger
3281+
BEFORE INSERT ON ltable
3282+
FOR EACH ROW EXECUTE PROCEDURE ftable_rowcount_trigf();
3283+
3284+
INSERT INTO parent VALUES ('AAA', 42), ('BBB', 42), ('AAA', 42), ('BBB', 42);
3285+
3286+
SELECT tableoid::regclass, * FROM parent;
3287+
3288+
-- Clean up
3289+
DROP FOREIGN TABLE ftable;
3290+
DROP TABLE batch_table;
3291+
DROP TRIGGER ftable_rowcount_trigger ON ltable;
3292+
DROP TABLE ltable;
3293+
DROP TABLE parent;
3294+
DROP FUNCTION ftable_rowcount_trigf;
3295+
32103296
-- ===================================================================
32113297
-- test asynchronous execution
32123298
-- ===================================================================

‎src/backend/executor/execMain.c

Lines changed: 1 addition & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -1257,6 +1257,7 @@ InitResultRelInfo(ResultRelInfo *resultRelInfo,
12571257
resultRelInfo->ri_ChildToRootMap = NULL;
12581258
resultRelInfo->ri_ChildToRootMapValid = false;
12591259
resultRelInfo->ri_CopyMultiInsertBuffer = NULL;
1260+
resultRelInfo->ri_ModifyTableState = NULL;
12601261
}
12611262

12621263
/*

‎src/backend/executor/execPartition.c

Lines changed: 7 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -934,6 +934,13 @@ ExecInitRoutingInfo(ModifyTableState *mtstate,
934934

935935
Assert(partRelInfo->ri_BatchSize >= 1);
936936

937+
/*
938+
* If doing batch insert, setup back-link so we can easily find the
939+
* mtstate again.
940+
*/
941+
if (partRelInfo->ri_BatchSize > 1)
942+
partRelInfo->ri_ModifyTableState = mtstate;
943+
937944
partRelInfo->ri_CopyMultiInsertBuffer = NULL;
938945

939946
/*

‎src/backend/executor/execUtils.c

Lines changed: 1 addition & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -127,6 +127,7 @@ CreateExecutorState(void)
127127
estate->es_result_relations = NULL;
128128
estate->es_opened_result_relations = NIL;
129129
estate->es_tuple_routing_result_relations = NIL;
130+
estate->es_insert_pending_result_relations = NIL;
130131
estate->es_trig_target_relations = NIL;
131132

132133
estate->es_param_list_info = NULL;

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