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Q.: Understanding Rushmore Technology
Message
De
25/08/1999 19:32:33
 
 
À
25/08/1999 19:17:43
Information générale
Forum:
Visual FoxPro
Catégorie:
Base de données, Tables, Vues, Index et syntaxe SQL
Divers
Thread ID:
00257424
Message ID:
00257697
Vues:
28
>>Hi all,
>>
>>The VFP 5.0 Developer's Guide states at page 396, parag. 5, " Avoid using indexes on fields that contain only a few discrete values such as a logical field"
>>
>
>Focussing on the first half of Mr. Richard's observation (quoted above), I would like to ask UT folks:
>
>Where is the dividing line?
>
>In other words how many is "few"?
>
>After I read the FPA article (subtitled "Less is more" right?), I took out some of my indexes. Now I'm about to go back and take out many more to see if I can speed up saves which are too slow without severely impacting queries.
>
>I working with a WAG of "ten or fewer different values". For instance, I have a one byte reservation status field which contains only the values: D, A, N, R, I, O, and C. My WAG rule tells me: No Index.
>
>What say you all?
>
>Peter Robinson

It depends on how many records are in the table and what effect it will have on queries based on that field.
Craig Berntson
MCSD, Microsoft .Net MVP, Grape City Community Influencer
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