Add test case for logical decoding of prepared transactions.

Andres Freund

contrib/test_decoding/sql/prepared.sql

@@ -0,0 +1,50 @@
+-- predictability
+SET synchronous_commit = on;
+SELECT 'init' FROM pg_create_logical_replication_slot('regression_slot', 'test_decoding');
+
+CREATE TABLE test_prepared1(id int);
+CREATE TABLE test_prepared2(id int);
+
+-- test simple successful use of a prepared xact
+BEGIN;
+INSERT INTO test_prepared1 VALUES (1);
+PREPARE TRANSACTION 'test_prepared#1';
+COMMIT PREPARED 'test_prepared#1';
+INSERT INTO test_prepared1 VALUES (2);
+
+-- test abort of a prepared xact
+BEGIN;
+INSERT INTO test_prepared1 VALUES (3);
+PREPARE TRANSACTION 'test_prepared#2';
+ROLLBACK PREPARED 'test_prepared#2';
+
+INSERT INTO test_prepared1 VALUES (4);
+
+-- test prepared xact containing ddl
+BEGIN;
+INSERT INTO test_prepared1 VALUES (5);
+ALTER TABLE test_prepared1 ADD COLUMN data text;
+INSERT INTO test_prepared1 VALUES (6, 'frakbar');
+PREPARE TRANSACTION 'test_prepared#3';
+
+-- test that we decode correctly while an uncommitted prepared xact
+-- with ddl exists.
+
+-- separate table because of the lock from the ALTER
+-- this will come before the '5' row above, as this commits before it.
+INSERT INTO test_prepared2 VALUES (7);
+
+COMMIT PREPARED 'test_prepared#3';
+
+-- make sure stuff still works
+INSERT INTO test_prepared1 VALUES (8);
+INSERT INTO test_prepared2 VALUES (9);
+
+-- cleanup
+DROP TABLE test_prepared1;
+DROP TABLE test_prepared2;
+
+-- show results
+SELECT data FROM pg_logical_slot_get_changes('regression_slot', NULL, NULL, 'include-xids', '0');
+
+SELECT pg_drop_replication_slot('regression_slot');