text: create serial s1;
  create serial s2;
  create table t(id varchar(10),cnt int);
  insert into t values('SN001',102);
  select * from t where id=s1.next_value;
  select * from t where id=s1.next_value and cnt=s2.next_value;
  select * from t where  cnt=s2.next_value and id=s1.next_value;
  select * from t where id=s1.next_value or cnt=s2.next_value;
  
  alter table t add column d date,t timestamp,c char(20);
  alter table t add constraint primary key (id);
  create reverse index ri on t(cnt);
  update t set d=sys_date,t=sys_timestamp,c=id;
  select * from t where d=s1.next_value;
  select * from t where t=s1.next_value;
  select * from t where c=s1.next_value;
  select * from t where d=s1.next_value and cnt=s2.next_value;
  select * from t where t=s1.next_value or cnt=s2.next_value;
  select * from t where c=s1.next_value and cnt=s2.next_value;
  select * from t where c=s1.next_value or cnt=s2.next_value;
  
  drop serial s1;
  drop serial s2;
  drop t;
  