text: autocommit off;
  create class cls_srt (id int, five int, ten int, dummy char(256));
  insert into cls_srt (id) values (1);
  insert into cls_srt (id) select id+  1 from cls_srt; --   2
  insert into cls_srt (id) select id+  2 from cls_srt; --   4
  insert into cls_srt (id) select id+  4 from cls_srt; --   8
  insert into cls_srt (id) select id+  8 from cls_srt; --  16
  insert into cls_srt (id) select id+ 16 from cls_srt; --  32
  insert into cls_srt (id) select id+ 32 from cls_srt; --  64
  insert into cls_srt (id) select id+ 64 from cls_srt; -- 128
  insert into cls_srt (id) select id+128 from cls_srt; -- 256
  insert into cls_srt (id) select id+256 from cls_srt; -- 512
  insert into cls_srt (id) select id+512 from cls_srt; --1024
  update cls_srt set five = mod(id, 5);    --#distinct:  5(0-4)
  update cls_srt set ten = mod(id, 10);    --#distinct: 10(0-9)
  update cls_srt set dummy = 'sort_test';  --#distinct:  1
  select i
  from (select id from cls_srt x order by id) as t(i)
  where rownum = 1;
  select i
  from (select id from cls_srt x order by id desc) as t(i)
  where rownum = 1;
  select count(*)
  from (select dummy, ten, five, id from cls_srt x) as t(i, j, k, l);
  select count(*)
  from (select dummy, dummy, dummy, id from cls_srt x) as t(i, j, k, l);
  select count(*)
  from (select five from cls_srt x) as t(i);
  select count(*)
  from (select ten from cls_srt x) as t(i);
  select count(*)
  from (select dummy from cls_srt x) as t(i);
  select count(*) 
  from (select distinct id from cls_srt x) as t(i);
  select count(*)
  from (select distinct dummy, ten, five, id from cls_srt x) as t(i, j, k, l);
  select count(*)
  from (select distinct dummy, dummy, dummy, id from cls_srt x) as t(i, j, k, l);
  select count(*)
  from (select distinct five from cls_srt x) as t(i);
  select count(*)
  from (select distinct ten from cls_srt x) as t(i);
  select count(*)
  from (select distinct dummy from cls_srt x) as t(i);
  rollback work;
  rollback;
  