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ARGHH! big table killing VFP - need strategy help!
Message
De
11/08/1999 02:12:48
Walter Meester
HoogkarspelPays-Bas
 
Information générale
Forum:
Visual FoxPro
Catégorie:
Autre
Divers
Thread ID:
00250826
Message ID:
00252370
Vues:
15
Stephen,

>Index on deleted() even if none are. Index on every column sepeciall if this is your trasnaction table.

Well, Your perception of the deleted() tag is an old one. Recently we believe that the deleted() tag is killing performance especially on large tables. Besides that if there are no deleted records there is no way that vfp could benefit from the deleted tag except for the following exceptions:

- You want to use FILTERED sql results.
(Alternative Use the table again and set a filter)

- You want to optimize the COUNT command.

In fact index on all columns is not a good idea. If you only index the most important (and selective) columns, you won't need the other columns (as they could be more like a burden than it helps you). When using a trancaction table it is generally a bad idea to have many indexes since this slows INSERT, UPDATE and DELETE actions significant.

Recently an article in fox advisor (or was it foxtalk ?) explained this whole topic.
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