text: --cast bit/blob/clob columns to TIMESTAMP(L)TZ types, in alter statement
  
  autocommit off;
  
  drop table if exists tz_test;
  
  create table tz_test(a bit(8), b bit varying, c blob, d clob);
  insert into tz_test values(B'10101111', X'abcdef', B'11001010', '2009-10-12 03:45:56 Africa/Ouagadougou');
  commit;
  
  --test: [er] cast bit/blob/clob columns to TIMESTAMP types
  alter table tz_test modify a timestamp;
  alter table tz_test modify b timestamp;
  alter table tz_test modify c timestamp;
  alter table tz_test modify d timestamp;
  
  --test: [er] cast bit/blob/clob columns to TIMESTAMPLTZ types
  alter table tz_test modify a timestamp with local time zone;
  alter table tz_test modify b timestamp with local time zone;
  alter table tz_test modify c timestamp with local time zone;
  alter table tz_test modify d timestamp with local time zone;
  
  --test: [er] cast bit/blob/clob columns to TIMESTAMPTZ types
  alter table tz_test modify a timestamp with time zone;
  alter table tz_test modify b timestamp with time zone;
  alter table tz_test modify c timestamp with time zone;
  alter table tz_test modify d timestamp with time zone;
  
  delete from tz_test;
  drop table tz_test;
  commit;
  
  set timezone 'Asia/Seoul';
  autocommit on;
  