postgresql/contrib/test_decoding/sql/slot.sql
Simon Riggs 9c7d06d606 Ability to advance replication slots
Ability to advance both physical and logical replication slots using a
new user function pg_replication_slot_advance().

For logical advance that means records are consumed as fast as possible
and changes are not given to output plugin for sending. Makes 2nd phase
(after we reached SNAPBUILD_FULL_SNAPSHOT) of replication slot creation
faster, especially when there are big transactions as the reorder buffer
does not have to deal with data changes and does not have to spill to
disk.

Author: Petr Jelinek
Reviewed-by: Simon Riggs
2018-01-17 11:38:34 +00:00

71 lines
2.9 KiB
PL/PgSQL

-- predictability
SET synchronous_commit = on;
SELECT 'init' FROM pg_create_logical_replication_slot('regression_slot_p', 'test_decoding');
SELECT 'init' FROM pg_create_logical_replication_slot('regression_slot_t', 'test_decoding', true);
SELECT pg_drop_replication_slot('regression_slot_p');
SELECT 'init' FROM pg_create_logical_replication_slot('regression_slot_p', 'test_decoding', false);
SELECT 'init' FROM pg_create_logical_replication_slot('regression_slot_t2', 'test_decoding', true);
-- here we want to start a new session and wait till old one is gone
select pg_backend_pid() as oldpid \gset
\c -
SET synchronous_commit = on;
do 'declare c int = 0;
begin
while (select count(*) from pg_replication_slots where active_pid = '
:'oldpid'
') > 0 loop c := c + 1; perform pg_sleep(0.01); end loop;
raise log ''slot test looped % times'', c;
end';
-- should fail because the temporary slots were dropped automatically
SELECT pg_drop_replication_slot('regression_slot_t');
SELECT pg_drop_replication_slot('regression_slot_t2');
-- permanent slot has survived
SELECT pg_drop_replication_slot('regression_slot_p');
-- test switching between slots in a session
SELECT 'init' FROM pg_create_logical_replication_slot('regression_slot1', 'test_decoding', true);
CREATE TABLE replication_example(id SERIAL PRIMARY KEY, somedata int, text varchar(120));
BEGIN;
INSERT INTO replication_example(somedata, text) VALUES (1, 1);
INSERT INTO replication_example(somedata, text) VALUES (1, 2);
COMMIT;
SELECT 'init' FROM pg_create_logical_replication_slot('regression_slot2', 'test_decoding', true);
INSERT INTO replication_example(somedata, text) VALUES (1, 3);
SELECT data FROM pg_logical_slot_get_changes('regression_slot1', NULL, NULL, 'include-xids', '0', 'skip-empty-xacts', '1');
SELECT data FROM pg_logical_slot_get_changes('regression_slot2', NULL, NULL, 'include-xids', '0', 'skip-empty-xacts', '1');
INSERT INTO replication_example(somedata, text) VALUES (1, 4);
INSERT INTO replication_example(somedata, text) VALUES (1, 5);
SELECT pg_current_wal_lsn() AS wal_lsn \gset
INSERT INTO replication_example(somedata, text) VALUES (1, 6);
SELECT end_lsn FROM pg_replication_slot_advance('regression_slot1', :'wal_lsn') \gset
SELECT slot_name FROM pg_replication_slot_advance('regression_slot2', pg_current_wal_lsn());
SELECT :'wal_lsn' = :'end_lsn';
SELECT data FROM pg_logical_slot_get_changes('regression_slot1', NULL, NULL, 'include-xids', '0', 'skip-empty-xacts', '1');
SELECT data FROM pg_logical_slot_get_changes('regression_slot2', NULL, NULL, 'include-xids', '0', 'skip-empty-xacts', '1');
DROP TABLE replication_example;
-- error
SELECT 'init' FROM pg_create_logical_replication_slot('regression_slot1', 'test_decoding', true);
-- both should error as they should be dropped on error
SELECT pg_drop_replication_slot('regression_slot1');
SELECT pg_drop_replication_slot('regression_slot2');