Re: Help with UNION query

On Sunday 04 September 2005 20:08, Andreas Joseph Krogh wrote:
> Replying to my self...

Again...

I managed to "reduse" my query to the following:

SELECT gr.groupname FROM onp_group gr, onp_user u
WHERE gr.id IN
(
SELECT g.id FROM
onp_group g, onp_user_group ug
WHERE g.groupname = ug.groupname AND ug.username = u.username
UNION
SELECT gc.child_id FROM
onp_group_children gc, onp_group g, onp_user_group ug
WHERE gc.group_id = g.id AND g.groupname = ug.groupname AND ug.username =
u.username
)
AND u.username = 'andreak';

But "EXPLAIN ANALYZE" tells me it's about 8x slower than this one:

SELECT gr.groupname FROM onp_group gr WHERE gr.id IN(
SELECT g.id
from onp_group g, onp_user_group ug
where g.groupname = ug.groupname AND ug.username = 'andreak'
UNION
SELECT gc.child_id
FROM onp_group_children gc, onp_group g, onp_user_group ug
WHERE gc.group_id = g.id AND g.groupname = ug.groupname AND ug.username =
'andreak'
);

So, the question stands: any idea on how to rewrite the lower wuery to only
specify "ug.username='andreak'" once?

--
Andreas Joseph Krogh <andreak(at)officenet(dot)no>
Senior Software Developer / Manager
gpg public_key: http://dev.officenet.no/~andreak/public_key.asc
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