SQL Server Performance Forum – Threads Archive

Joining Tables

SELECT t1.Field1
FROM Table1 t1
JOIN Table2 t2 ON t2.Field1 = t1.Field2
WHERE t1.Field1 NOT IN
(SELECT Field1 FROM Table3 WHERE ID = 1) it’s too slow if I have too many records in Table3. If I could do this in some other way, maybe (or most probably a join) then it would help in the problem in my other post. Thanks.

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?? what was the trouble? Satya SKJ
Moderator
http://www.SQL-Server-Performance.Com/forum
This posting is provided “AS IS” with no rights for the sake of knowledge sharing.

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http://www.sql-server-performance.com/tuning_joins.asp
http://www.sql-server-performance.com/developers_tuning_tutorial.asp Satya SKJ
Moderator
http://www.SQL-Server-Performance.Com/forum
This posting is provided “AS IS” with no rights for the sake of knowledge sharing.

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Did you try something like this? SELECT t1.Field1
FROM Table1 t1
JOIN Table2 t2 ON t2.Field1 = t1.Field2
LEFT JOIN Table3 t3 ON t3.Field1 = t1.Field2 AND t3.ID <> 1

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hi chopeen! I haven’t tried it, it worked anyway. Is there a big difference then, regarding performance?

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hi again! chopeen, i tried the query you gave me and it gave me different result with the one i have. thanks.

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<blockquote id="quote"><font size="1" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by blueFrench</i><br /><br />I haven’t tried it, it worked anyway. Is there a big difference then, regarding performance?<br /><hr height="1" noshade id="quote"></font id="quote"></blockquote id="quote"><br /><br />It’s hard to tell. [<img src=’/community/emoticons/emotion-2.gif’ alt=’‘ />] Since I do not know what difference we are talking about.<br /><br /><i>My query and yours from your first post in this topic?</i><br />It’s you who said it is too slow.<br /><br /><i>My query and your new one?</i><br />I haven’t seen the new one.<br /><br />–<br /><br />

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hi chopeen! what i mean is that when you try my code (the one posted here) and the one you suggested, it will give us diff. result. thanks.

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I was afraid of this. I created some sample data to test my and your query. Both gave me the same results, so I hoped it’s gonna work fine.

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