Performance in subconsult

Hello there!

I have the next query:

psql# select * from table1 t1 where not exists (select * from table2 t2
where t2.id = t1.id);

The execution of this uses more than 90% of my CPU performance and the
answer is slow...

Is there any wrong on my query?

Thanks for the posible answers.

******************************************************************************
Direccion General de Servicios de Computo Academico
Productos Interactivos
Sonia Sanchez Diaz
e-mail: sonny@piaget.dgsca.unam.mx
tel: (5)6-22-81-13
ICQ: 127002683
******************************************************************************