text: -- trans.test
  -- 
  -- execsql {
  --       BEGIN;
  --       CREATE TEMP TABLE t3 AS SELECT * FROM t2;
  --       INSERT INTO t2 SELECT * FROM t3;
  --       DROP INDEX i2x;
  --       DROP INDEX i2y;
  --       CREATE INDEX i3a ON t3(x);
  --       ROLLBACK;
  --       SELECT md5sum(x,y,z) FROM t2;
  -- }
  BEGIN;
  CREATE TEMP TABLE t3 AS SELECT * FROM t2;
  INSERT INTO t2 SELECT * FROM t3;
  DROP INDEX i2x;
  DROP INDEX i2y;
  CREATE INDEX i3a ON t3(x);
  ROLLBACK;
  SELECT md5sum(x,y,z) FROM t2;