text: -- thread001.test
  -- 
  -- execsql {
  --       CREATE TABLE ab(a INTEGER PRIMARY KEY, b);
  --       CREATE INDEX ab_i ON ab(b);
  --       INSERT INTO ab SELECT NULL, md5sum(a, b) FROM ab;
  --       SELECT count(*) FROM ab;
  -- }
  CREATE TABLE ab(a INTEGER PRIMARY KEY, b);
  CREATE INDEX ab_i ON ab(b);
  INSERT INTO ab SELECT NULL, md5sum(a, b) FROM ab;
  SELECT count(*) FROM ab;