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Why is it so slow?
Message
De
15/08/2002 10:31:50
Hilmar Zonneveld
Independent Consultant
Cochabamba, Bolivie
 
 
À
15/08/2002 10:10:34
Information générale
Forum:
Visual FoxPro
Catégorie:
Base de données, Tables, Vues, Index et syntaxe SQL
Divers
Thread ID:
00689948
Message ID:
00689972
Vues:
17
>Hi
>
>I have a table that contains 192,216 records, 177,493 of these are deleted records.
>
>I have a DELETED() Index on the table, yet when I run a command like SCAN FOR...ENDSCAN on an indexed field, it takes absolutely ages. This is over a 1MB WAN by the way, but it still should only take seconds, it takes minutes, about 3 to be exact.
>
>What am I doing wrong here?
>
>Thanks
>Kev

You should avoid two things:

1) Having ca. 90% of the records deleted. Plan a PACK at least once a month; more frequent depending on the amount of changes done. You can create an automated procedure that will do this at midnight.

2) Having an index on DELETED(). This can actually slow things down. See my FAQ on "Rushmore" for details.

HTH, Hilmar.
Difference in opinions hath cost many millions of lives: for instance, whether flesh be bread, or bread be flesh; whether whistling be a vice or a virtue; whether it be better to kiss a post, or throw it into the fire... (from Gulliver's Travels)
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