Обсуждение: not exists clause

Golly,

> I cannot get the "not exists" clause of ANSI SQL to execute correctly.
> select t.col11, t.col1... from table1 t where not exists (select 1 from
> table2 where col2 = t.col1);
> table1 has 40M + rows. if that matters.
>
> OS is FreeBSD 6.2, postgresql version 8.2.6

You'll have to post the actual query and error message.  WHERE NOT EXISTS
has been supported since version 7.1.

--
--Josh

Josh Berkus
PostgreSQL @ Sun
San Francisco

S Golly wrote:
> I cannot get the "not exists" clause of ANSI SQL to execute correctly.
> select t.col11, t.col1... from table1 t where not exists (select 1 from
> table2 where col2 = t.col1);
> table1 has 40M + rows. if that matters.
>
> OS is FreeBSD 6.2, postgresql version 8.2.6
>
> Is it not supported or a bug ?
> thank you for your support.

This is really not a performance question, but a general SQL question.

select * from t1

f1
--
1
2
3

select * from t2

f1
--
1
2

select * from t1
where not exists
(
select 1
from t2
where t2.f1 = t1.f1
)

f1
--
3

--
Guy Rouillier