-- test that we can insert the result of a get_changes call into a
-- logged relation. That's really not a good idea in practical terms,
-- but provides a nice test.
-- predictability
SET synchronous_commit = on;
SELECT 'init' FROM pg_create_logical_replication_slot('regression_slot', 'test_decoding');
 ?column? 
----------
 init
(1 row)

-- slot works
SELECT data FROM pg_logical_slot_get_changes('regression_slot', NULL, NULL, 'include-xids', '0', 'skip-empty-xacts', '1');
 data 
------
(0 rows)

-- create some changes
CREATE TABLE somechange(id serial primary key);
INSERT INTO somechange DEFAULT VALUES;
CREATE TABLE changeresult AS
    SELECT data FROM pg_logical_slot_get_changes('regression_slot', NULL, NULL, 'include-xids', '0', 'skip-empty-xacts', '1');
SELECT * FROM changeresult;
                      data                      
------------------------------------------------
 BEGIN
 table public.somechange: INSERT: id[integer]:1
 COMMIT
(3 rows)

INSERT INTO changeresult
    SELECT data FROM pg_logical_slot_peek_changes('regression_slot', NULL, NULL, 'include-xids', '0', 'skip-empty-xacts', '1');
INSERT INTO changeresult
    SELECT data FROM pg_logical_slot_get_changes('regression_slot', NULL, NULL, 'include-xids', '0', 'skip-empty-xacts', '1');
SELECT * FROM changeresult;
                                                                       data                                                                       
--------------------------------------------------------------------------------------------------------------------------------------------------
 BEGIN
 table public.somechange: INSERT: id[integer]:1
 COMMIT
 BEGIN
 table public.changeresult: INSERT: data[text]:'BEGIN'
 table public.changeresult: INSERT: data[text]:'table public.somechange: INSERT: id[integer]:1'
 table public.changeresult: INSERT: data[text]:'COMMIT'
 COMMIT
 BEGIN
 table public.changeresult: INSERT: data[text]:'BEGIN'
 table public.changeresult: INSERT: data[text]:'table public.somechange: INSERT: id[integer]:1'
 table public.changeresult: INSERT: data[text]:'COMMIT'
 COMMIT
 BEGIN
 table public.changeresult: INSERT: data[text]:'BEGIN'
 table public.changeresult: INSERT: data[text]:'table public.changeresult: INSERT: data[text]:''BEGIN'''
 table public.changeresult: INSERT: data[text]:'table public.changeresult: INSERT: data[text]:''table public.somechange: INSERT: id[integer]:1'''
 table public.changeresult: INSERT: data[text]:'table public.changeresult: INSERT: data[text]:''COMMIT'''
 table public.changeresult: INSERT: data[text]:'COMMIT'
 COMMIT
(20 rows)

DROP TABLE changeresult;
DROP TABLE somechange;
-- check calling logical decoding from pl/pgsql
CREATE FUNCTION slot_changes_wrapper(slot_name name) RETURNS SETOF TEXT AS $$
BEGIN
  RETURN QUERY
    SELECT data FROM pg_logical_slot_peek_changes(slot_name, NULL, NULL, 'include-xids', '0', 'skip-empty-xacts', '1');
END$$ LANGUAGE plpgsql;
SELECT * FROM slot_changes_wrapper('regression_slot');
                                                                                          slot_changes_wrapper                                                                                          
--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
 BEGIN
 table public.changeresult: INSERT: data[text]:'BEGIN'
 table public.changeresult: INSERT: data[text]:'table public.changeresult: INSERT: data[text]:''BEGIN'''
 table public.changeresult: INSERT: data[text]:'table public.changeresult: INSERT: data[text]:''table public.somechange: INSERT: id[integer]:1'''
 table public.changeresult: INSERT: data[text]:'table public.changeresult: INSERT: data[text]:''COMMIT'''
 table public.changeresult: INSERT: data[text]:'COMMIT'
 table public.changeresult: INSERT: data[text]:'BEGIN'
 table public.changeresult: INSERT: data[text]:'table public.changeresult: INSERT: data[text]:''BEGIN'''
 table public.changeresult: INSERT: data[text]:'table public.changeresult: INSERT: data[text]:''table public.changeresult: INSERT: data[text]:''''BEGIN'''''''
 table public.changeresult: INSERT: data[text]:'table public.changeresult: INSERT: data[text]:''table public.changeresult: INSERT: data[text]:''''table public.somechange: INSERT: id[integer]:1'''''''
 table public.changeresult: INSERT: data[text]:'table public.changeresult: INSERT: data[text]:''table public.changeresult: INSERT: data[text]:''''COMMIT'''''''
 table public.changeresult: INSERT: data[text]:'table public.changeresult: INSERT: data[text]:''COMMIT'''
 table public.changeresult: INSERT: data[text]:'COMMIT'
 COMMIT
(14 rows)

SELECT data FROM pg_logical_slot_get_changes('regression_slot', NULL, NULL, 'include-xids', '0', 'skip-empty-xacts', '1');
                                                                                                  data                                                                                                  
--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
 BEGIN
 table public.changeresult: INSERT: data[text]:'BEGIN'
 table public.changeresult: INSERT: data[text]:'table public.changeresult: INSERT: data[text]:''BEGIN'''
 table public.changeresult: INSERT: data[text]:'table public.changeresult: INSERT: data[text]:''table public.somechange: INSERT: id[integer]:1'''
 table public.changeresult: INSERT: data[text]:'table public.changeresult: INSERT: data[text]:''COMMIT'''
 table public.changeresult: INSERT: data[text]:'COMMIT'
 table public.changeresult: INSERT: data[text]:'BEGIN'
 table public.changeresult: INSERT: data[text]:'table public.changeresult: INSERT: data[text]:''BEGIN'''
 table public.changeresult: INSERT: data[text]:'table public.changeresult: INSERT: data[text]:''table public.changeresult: INSERT: data[text]:''''BEGIN'''''''
 table public.changeresult: INSERT: data[text]:'table public.changeresult: INSERT: data[text]:''table public.changeresult: INSERT: data[text]:''''table public.somechange: INSERT: id[integer]:1'''''''
 table public.changeresult: INSERT: data[text]:'table public.changeresult: INSERT: data[text]:''table public.changeresult: INSERT: data[text]:''''COMMIT'''''''
 table public.changeresult: INSERT: data[text]:'table public.changeresult: INSERT: data[text]:''COMMIT'''
 table public.changeresult: INSERT: data[text]:'COMMIT'
 COMMIT
(14 rows)

SELECT 'stop' FROM pg_drop_replication_slot('regression_slot');
 ?column? 
----------
 stop
(1 row)