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Partial vs Full Optimization
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De
07/02/2001 07:43:29
 
 
À
07/02/2001 06:43:48
Information générale
Forum:
Visual FoxPro
Catégorie:
Codage, syntaxe et commandes
Divers
Thread ID:
00473308
Message ID:
00473369
Vues:
24
Hi Alex,

Perhaps "originally documented by. . ." would be more accurate.

Cheers,

JimN

>Walter,
>
>Correct but I wouldn't use a reserved word as a tag name, but something else instead:
>INDEX ON DELETED() TAG DELREC
>
>Also, he could check the info on the wiki over Rushmore optimization and this problem, originally discovered by Chris Probst.
>
>http://fox.wikis.com/wc.dll?Wiki~NonDiscriminatingIndex
>http://fox.wikis.com/wc.dll?Wiki~RushMore~VFP
>
>>>>>>>>>>>>>>>>>>>>
>>Please don't be fooled by the idea that fully optimized is the fasted way to do a SQL select, it isn't. Fully optimized simply indicates that the query uses indexes for each component of the whereclause. If you've got SET DELETE to ON, you'll have to add an INDEX ON DELETED() TAG DELETED() to be able to fully optimize queries.
>>
>>However, the DELETED() tag, because of its low selective nature, in far the most cases only slows queries down than it speeds them up. Partial optimization often is far better than fully optimized, esspecially on a network.
>>>>>>>>>>>>>>>>>>>>
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