text: --
  -- XC_SEQUENCE
  --
  
  -- Check of callback mechanisms on GTM
  
  -- Sequence DROP and CREATE
  -- Rollback a creation
  BEGIN;
  CREATE SEQUENCE xc_sequence_1;
  SELECT nextval('xc_sequence_1'); -- ok
  ROLLBACK;
  SELECT nextval('xc_sequence_1'); -- fail
  -- Commit a creation
  BEGIN;
  CREATE SEQUENCE xc_sequence_1;
  SELECT nextval('xc_sequence_1'); -- ok
  COMMIT;
  SELECT nextval('xc_sequence_1'); -- ok
  -- Rollback a drop
  BEGIN;
  DROP SEQUENCE xc_sequence_1;
  SELECT nextval('xc_sequence_1'); -- fail
  ROLLBACK;
  SELECT nextval('xc_sequence_1'); -- ok, previous transaction failed
  -- Commit a drop
  BEGIN;
  DROP SEQUENCE xc_sequence_1;
  COMMIT;
  SELECT nextval('xc_sequence_1'); -- fail
  
  -- SEQUENCE RENAME TO
  -- Rollback a renaming
  CREATE SEQUENCE xc_sequence_1;
  SELECT nextval('xc_sequence_1'); -- ok
  BEGIN;
  ALTER SEQUENCE xc_sequence_1 RENAME TO xc_sequence_2;
  SELECT nextval('xc_sequence_2'); -- ok
  ROLLBACK;
  SELECT nextval('xc_sequence_1'); -- ok
  -- Commit a renaming
  BEGIN;
  ALTER SEQUENCE xc_sequence_1 RENAME TO xc_sequence_2;
  SELECT nextval('xc_sequence_2'); -- ok
  COMMIT;
  SELECT nextval('xc_sequence_2'); -- ok
  DROP SEQUENCE xc_sequence_2;
  
  -- Columns with SERIAL
  -- Serial sequence is named xc_sequence_tab1_col2_seq
  CREATE TABLE xc_sequence_tab1 (col1 int, col2 serial) DISTRIBUTE BY ROUNDROBIN;
  -- Some data
  INSERT INTO xc_sequence_tab1 VALUES (1, DEFAULT);
  INSERT INTO xc_sequence_tab1 VALUES (2, DEFAULT);
  SELECT col1, col2 FROM xc_sequence_tab1 ORDER BY 1;
  -- Rollback a SERIAL column drop
  BEGIN;
  ALTER TABLE xc_sequence_tab1 DROP COLUMN col2;
  INSERT INTO xc_sequence_tab1 VALUES (3);
  SELECT col1 FROM xc_sequence_tab1 ORDER BY 1;
  ROLLBACK;
  SELECT nextval('xc_sequence_tab1_col2_seq'); -- ok
  -- Commit a SERIAL column drop
  BEGIN;
  ALTER TABLE xc_sequence_tab1 DROP COLUMN col2;
  INSERT INTO xc_sequence_tab1 VALUES (3);
  SELECT col1 FROM xc_sequence_tab1 ORDER BY 1;
  COMMIT;
  DROP TABLE xc_sequence_tab1;
  -- Need to recreate here, serial column is no more
  CREATE TABLE xc_sequence_tab1 (col1 int, col2 serial) DISTRIBUTE BY ROUNDROBIN;
  INSERT INTO xc_sequence_tab1 VALUES (1234, DEFAULT);
  SELECT col1, col2 FROM xc_sequence_tab1 ORDER BY 1;
  -- Rollback of a table with SERIAL
  BEGIN;
  DROP TABLE xc_sequence_tab1;
  ROLLBACK;
  SELECT nextval('xc_sequence_tab1_col2_seq'); -- ok
  -- Commit of a table with SERIAL
  BEGIN;
  DROP TABLE xc_sequence_tab1;
  COMMIT;
  -- Recreate a sequence with the same name as previous SERIAL one
  CREATE SEQUENCE xc_sequence_tab1_col2_seq START 2344;
  SELECT nextval('xc_sequence_tab1_col2_seq'); -- ok
  DROP SEQUENCE xc_sequence_tab1_col2_seq;
  