[pengpeng]

I have two tables,

create table t1(
col11 int,
col12 int,
col13 int)

and

create table t2(
col21 int,
col22 int)

I tried to write a sql statement as follow to get what exist in t1 but not in t2 and vice versa.

>select * from t1
where (col11, col12) not exists (select col21, col22 from t2)

I got the error:
Incorrect syntax near ','.

Then I had to using,
>select *
from t1
where t1.col11 not in ( select t2.col21
from t2
where t1.col11=t2.col21
and t1.col12=t2.col22)
and t1.col12 not in ( select t2.col21
from t2
where t1.col11=t2.col21
and t1.col12=t2.col22)

It works. But it takes a long time to finishe. Is there a way to use exist on multiple columns in where clause, or an other way to write my sql to improve performance?

Thanks.
Pengpeng