Re: question on JOIN and WHERE clause
От | Henshall, Stuart - WCP |
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Тема | Re: question on JOIN and WHERE clause |
Дата | |
Msg-id | E2870D8CE1CCD311BAF50008C71EDE8E01F748CA@MAIL_EXCHANGE обсуждение исходный текст |
Ответ на | question on JOIN and WHERE clause (Wei Weng <wweng@kencast.com>) |
Список | pgsql-sql |
<p><font size="2">I believe it pushes any clauses it can into the individual sub-plans, and anything it can't it leaves abovethe join.</font><br /><font size="2">- Stuart</font><p><font size="2">> -----Original Message-----</font><br /><fontsize="2">> From: Wei Weng [<a href="mailto:wweng@kencast.com">mailto:wweng@kencast.com</a>]</font><br /><font size="2">>Sent: 30 May 2002 18:07</font><br /><font size="2">> To: pgsql-sql@postgresql.org</font><br /><font size="2">>Subject: question on JOIN and WHERE clause</font><br /><font size="2">> </font><br /><font size="2">></font><br /><font size="2">> Does the SQL optimizer process the JOIN first then add WHERE</font><br /><fontsize="2">> constraintson it or it processes the WHERE clause and JOIN at the same</font><br /><font size="2">>time?</font><br /><font size="2">> </font><br /><font size="2">> Thanks!</font><br /><font size="2">></font><br /><font size="2">> </font><br /><font size="2">> </font><br /><font size="2">> -- </font><br/><font size="2">> Wei Weng</font><br /><font size="2">> Network Software Engineer</font><br /><font size="2">>KenCast Inc.</font><br /><font size="2">> </font><br /><font size="2">> </font><br /><font size="2">></font>
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