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Performance issues when querying shared data
Message
De
07/10/2005 12:06:29
 
 
À
07/10/2005 07:24:57
Information générale
Forum:
Visual FoxPro
Catégorie:
Client/serveur
Versions des environnements
Visual FoxPro:
VFP 6
Divers
Thread ID:
01057091
Message ID:
01057228
Vues:
9
>Mathias
>
>Sounds reasonable. I would recommend that where poss. you use the join conditions in your SQL (e.g. "inner join OtherTable on ...", rather than "where ...". It can speed up your queries by an order of magnitude.
>
Terry:

A while ago I posted a message "WHERE vs JOIN" in which I asked about this. The consensus of the replies (if I've understood correctly) is that JOIN produces code which is more readable, more flexible, and can produce more accurate results when using outer joins. But by the time the query optimizer was finished, there were only marginal differences in performance. Can you give me some information on what conditions might lead to an order of magnitude difference in speed using JOIN rather than WHERE?

Thanks.........Rich
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