Re: join query question

From: mel <jmel_at_mailnews.com>
Date: 21 Jun 2001 16:34:09 -0500
Message-ID: <3b3267af$0$269$45beb828@newscene.com>

It depends on a number of factors. A hash anti join may be the best.

You can use

not in
not exists
minus
outer join using nulls
hash anti-join

in order from worse to best most texts list

not in
minus
not exists
outer join using nulls
hash anti-join

In article <3b321a79.256948140_at_news.alt.net>, SPAMBLOCK.Maxwell_Smart_at_ThePentagon.com.SPAMBLOCK (Brian Tkatch) wrote:
>On Thu, 21 Jun 2001 15:37:19 GMT, vk02720 <nospam_at_newsranger.com>
>wrote:
>
>>table A and table B both have a common field empnum.
>>What is the most optimal query to get the data from table A which is not in
the
>>table B using empnum ?
>>
>>TIA
>
>I would assume
>
>SELECT * FROM Table_A WHERE NOT EXISTS
> (SELECT * FROM Table_B WHERE Empnum = Table_A.Empnum);
Received on Thu Jun 21 2001 - 16:34:09 CDT