Walter Meester
HoogkarspelPays-Bas
Information générale
Catégorie:
Base de données, Tables, Vues, Index et syntaxe SQL
Versions des environnements
Network:
Windows 2000 Server
>Walter,
>
>>BTW, get rid off the deleted tag. It does not speed up your query (except in very specific circumstances). Full optimization does not mean that it is most optimal.
>
>that used to be one of my standard first checks. It changed to making sure if the index was at least binary and then thinking on deleting<g>.
>On the off chance that the deleted() index helps at least somewhere in the app the slight slurp of the pure bitmap of a binary index helps MUCH more than I had imagined after first readin about it.
I've gone through that before. An index on deleted() is about useless except in very specific case. None of them is particulary usefull (except for COUNT()). The low selectivity does not speed up your queries, esspecially if your tables do not contain or few deleted records.
I'm sure what you've seen, but under most conditions, it is technically impossible that even a binary index would speed up anything beyond a few milliseconds.
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