mirror/postgresql
2
0
Fork 0
mirror of https://git.postgresql.org/git/postgresql.git synced 2025-02-23 19:39:53 +08:00
Code Issues Packages Projects Releases Wiki Activity

Fix skip-empty-xacts with sequences in test_decoding

Browse Source 
Regression tests need to use skip-empty-xacts = false, because there
might be accidental concurrent activity (like autovacuum), particularly
on slow machines. The tests added by 80901b3291 failed to do that in a
couple places, triggering occasional failures on buildfarm.

Fixing the tests however uncovered a bug in the code, because sequence
callbacks did not handle skip-empty-xacts properly. For trasactional
increments we need to check/update the xact_wrote_changes flag, and emit
the BEGIN if it's the first change in the transaction.

Reported-by: Andres Freund
Discussion: https://postgr.es/m/20220212220413.b25amklo7t4xb7ni%40alap3.anarazel.de
This commit is contained in:
Tomas Vondra 2022-02-12 23:50:42 +01:00
parent faa189c932
commit b779d7d8fd
3 changed files with 31 additions and 11 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

12
contrib/test_decoding/expected/sequence.out
View File

@ -87,7 +87,7 @@ SELECT nextval('test_sequence');
(1 row)
-- show results and drop sequence
SELECT data FROM pg_logical_slot_get_changes('regression_slot', NULL, NULL, 'include-xids', '0', 'skip-empty-xacts', '0');
SELECT data FROM pg_logical_slot_get_changes('regression_slot', NULL, NULL, 'include-xids', '0', 'skip-empty-xacts', '1');
data
----------------------------------------------------------------------------------------
BEGIN
@ -236,7 +236,7 @@ SELECT nextval('test_table_a_seq');
(1 row)
DROP TABLE test_table;
SELECT data FROM pg_logical_slot_get_changes('regression_slot', NULL, NULL, 'include-xids', '0', 'skip-empty-xacts', '0');
SELECT data FROM pg_logical_slot_get_changes('regression_slot', NULL, NULL, 'include-xids', '0', 'skip-empty-xacts', '1');
data
-------------------------------------------------------------------------------------------
BEGIN
@ -245,9 +245,7 @@ SELECT data FROM pg_logical_slot_get_changes('regression_slot', NULL, NULL, 'inc
sequence public.test_table_a_seq: transactional:0 last_value: 33 log_cnt: 0 is_called:1
sequence public.test_table_a_seq: transactional:0 last_value: 3000 log_cnt: 0 is_called:1
sequence public.test_table_a_seq: transactional:0 last_value: 3033 log_cnt: 0 is_called:1
BEGIN
COMMIT
(8 rows)
(6 rows)
-- savepoint test on table with serial column
BEGIN;
@ -259,7 +257,7 @@ INSERT INTO test_table (b) VALUES (300);
ROLLBACK TO SAVEPOINT a;
DROP TABLE test_table;
COMMIT;
SELECT data FROM pg_logical_slot_get_changes('regression_slot', NULL, NULL, 'include-xids', '0', 'skip-empty-xacts', '0');
SELECT data FROM pg_logical_slot_get_changes('regression_slot', NULL, NULL, 'include-xids', '0', 'skip-empty-xacts', '1');
data
-----------------------------------------------------------------------------------------
BEGIN
@ -308,7 +306,7 @@ SELECT * FROM test_sequence;
DROP SEQUENCE test_sequence;
COMMIT;
SELECT data FROM pg_logical_slot_get_changes('regression_slot', NULL, NULL, 'include-xids', '0', 'skip-empty-xacts', '0');
SELECT data FROM pg_logical_slot_get_changes('regression_slot', NULL, NULL, 'include-xids', '0', 'skip-empty-xacts', '1');
data
----------------------------------------------------------------------------------------
BEGIN

8
contrib/test_decoding/sql/sequence.sql
View File

@ -28,7 +28,7 @@ SELECT setval('test_sequence', 3500, false);
SELECT nextval('test_sequence');
-- show results and drop sequence
SELECT data FROM pg_logical_slot_get_changes('regression_slot', NULL, NULL, 'include-xids', '0', 'skip-empty-xacts', '0');
SELECT data FROM pg_logical_slot_get_changes('regression_slot', NULL, NULL, 'include-xids', '0', 'skip-empty-xacts', '1');
DROP SEQUENCE test_sequence;
-- rollback on sequence creation and update
@ -87,7 +87,7 @@ SELECT * from test_table_a_seq;
SELECT nextval('test_table_a_seq');
DROP TABLE test_table;
SELECT data FROM pg_logical_slot_get_changes('regression_slot', NULL, NULL, 'include-xids', '0', 'skip-empty-xacts', '0');
SELECT data FROM pg_logical_slot_get_changes('regression_slot', NULL, NULL, 'include-xids', '0', 'skip-empty-xacts', '1');
-- savepoint test on table with serial column
BEGIN;
@ -99,7 +99,7 @@ INSERT INTO test_table (b) VALUES (300);
ROLLBACK TO SAVEPOINT a;
DROP TABLE test_table;
COMMIT;
SELECT data FROM pg_logical_slot_get_changes('regression_slot', NULL, NULL, 'include-xids', '0', 'skip-empty-xacts', '0');
SELECT data FROM pg_logical_slot_get_changes('regression_slot', NULL, NULL, 'include-xids', '0', 'skip-empty-xacts', '1');
-- savepoint test on table with serial column
BEGIN;
@ -114,6 +114,6 @@ ROLLBACK TO SAVEPOINT a;
SELECT * FROM test_sequence;
DROP SEQUENCE test_sequence;
COMMIT;
SELECT data FROM pg_logical_slot_get_changes('regression_slot', NULL, NULL, 'include-xids', '0', 'skip-empty-xacts', '0');
SELECT data FROM pg_logical_slot_get_changes('regression_slot', NULL, NULL, 'include-xids', '0', 'skip-empty-xacts', '1');
SELECT pg_drop_replication_slot('regression_slot');

22
contrib/test_decoding/test_decoding.c
View File

@ -774,10 +774,21 @@ pg_decode_sequence(LogicalDecodingContext *ctx, ReorderBufferTXN *txn,
int64 last_value, int64 log_cnt, bool is_called)
{
TestDecodingData *data = ctx->output_plugin_private;
TestDecodingTxnData *txndata = txn->output_plugin_private;
if (!data->include_sequences)
return;
/* output BEGIN if we haven't yet, but only for the transactional case */
if (transactional)
{
if (data->skip_empty_xacts && !txndata->xact_wrote_changes)
{
pg_output_begin(ctx, data, txn, false);
}
txndata->xact_wrote_changes = true;
}
OutputPluginPrepareWrite(ctx, true);
appendStringInfoString(ctx->out, "sequence ");
appendStringInfoString(ctx->out,
@ -994,10 +1005,21 @@ pg_decode_stream_sequence(LogicalDecodingContext *ctx, ReorderBufferTXN *txn,
int64 last_value, int64 log_cnt, bool is_called)
{
TestDecodingData *data = ctx->output_plugin_private;
TestDecodingTxnData *txndata = txn->output_plugin_private;
if (!data->include_sequences)
return;
/* output BEGIN if we haven't yet, but only for the transactional case */
if (transactional)
{
if (data->skip_empty_xacts && !txndata->xact_wrote_changes)
{
pg_output_begin(ctx, data, txn, false);
}
txndata->xact_wrote_changes = true;
}
OutputPluginPrepareWrite(ctx, true);
appendStringInfoString(ctx->out, "streaming sequence ");
appendStringInfoString(ctx->out,