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-- create function
CREATE FUNCTION table_log ()
    RETURNS TRIGGER
    AS '$libdir/table_log' LANGUAGE 'C';
CREATE FUNCTION "table_log_restore_table" (VARCHAR, VARCHAR, CHAR, CHAR, CHAR, TIMESTAMPTZ, CHAR, INT, INT)
    RETURNS VARCHAR
    AS '$libdir/table_log', 'table_log_restore_table' LANGUAGE 'C';
CREATE FUNCTION "table_log_restore_table" (VARCHAR, VARCHAR, CHAR, CHAR, CHAR, TIMESTAMPTZ, CHAR, INT)
    RETURNS VARCHAR
    AS '$libdir/table_log', 'table_log_restore_table' LANGUAGE 'C';
CREATE FUNCTION "table_log_restore_table" (VARCHAR, VARCHAR, CHAR, CHAR, CHAR, TIMESTAMPTZ, CHAR)
    RETURNS VARCHAR
    AS '$libdir/table_log', 'table_log_restore_table' LANGUAGE 'C';
CREATE FUNCTION "table_log_restore_table" (VARCHAR, VARCHAR, CHAR, CHAR, CHAR, TIMESTAMPTZ)
    RETURNS VARCHAR
    AS '$libdir/table_log', 'table_log_restore_table' LANGUAGE 'C';

-- create demo table
CREATE TABLE test (
  id                    INT                 NOT NULL
                                            PRIMARY KEY,
  name                  VARCHAR(20)         NOT NULL
);

-- create the table without data from demo table
SELECT * INTO test_log FROM test LIMIT 0;
ALTER TABLE test_log ADD COLUMN trigger_mode VARCHAR(10);
ALTER TABLE test_log ADD COLUMN trigger_tuple VARCHAR(5);
ALTER TABLE test_log ADD COLUMN trigger_changed TIMESTAMPTZ;
ALTER TABLE test_log ADD COLUMN trigger_id BIGINT;
CREATE SEQUENCE test_log_id;
SELECT SETVAL('test_log_id', 1, FALSE);
ALTER TABLE test_log ALTER COLUMN trigger_id SET DEFAULT NEXTVAL('test_log_id');

-- create trigger
CREATE TRIGGER test_log_chg AFTER UPDATE OR INSERT OR DELETE ON test FOR EACH ROW
               EXECUTE PROCEDURE table_log();

-- test trigger
INSERT INTO test VALUES (1, 'name');
SELECT * FROM test;
SELECT * FROM test_log;
UPDATE test SET name='other name' WHERE id=1;
SELECT * FROM test;
SELECT * FROM test_log;

-- create restore table
SELECT table_log_restore_table('test', 'id', 'test_log', 'test_log_id', 'test_recover', NOW());
SELECT * FROM test_recover;