text: select pg_sleep(3);
  select current_timestamp;
  drop table tx;
  insert into cmpts values(3,current_timestamp);
  select current_timestamp;
  select true from cmpts r,cmpts n, cmpts d
  where r.c1 = 1 and n.c1 = 2 and d.c1 = 3
  and r.ts< n.ts and n.ts < d.ts;
  