Re: [GENERAL] select ... FROM ... WHERE .. IN (select ...) takes FOREVER... Can someone help me optimize this?

[Patrick Welche]

On Sat, Mar 18, 2000 at 09:34:37PM -0500, Chris Gokey wrote:
> 
> I was hoping that someone could help me optimize this query.  This takes
> FOREVER under PostgreSQL.
> 
> select distinct data_center, center_long from de_center where de_center.de_id
> in ( SELECT distinct de_parameters.de_id  FROM de_parameters WHERE
> de_parameters.topic = 'ATMOSPHERE') order by data_center;

Not sure, but how about

select data_center, center_long from de_center
  where exists
    ( SELECT * FROM de_parameters WHERE
            de_parameters.topic = 'ATMOSPHERE'
        and de_center.de_id = de_parameters.de_id
    )
  order by data_center;

?
(Wish I could test it first...)

Cheers,

Patrick