Information générale
Catégorie:
Base de données, Tables, Vues, Index et syntaxe SQL
Pierre,
Your observation is correct - there is a discrepancy in the documentation and it errs in suggesting and index on deleted() is a wise thing to do.
Funny thing about this is that at one time an index on DELETED() *did* seem to have a major positive impact on just about any SQL statement's performance, but more recently it has proven to be different.
Today, in fact, the general recommendation is to avoid such a TAG except in very particular circumstance (which are highly dependent on the specific data and your coding practises).
Cheers,
Jim N
>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"
>
>So then why should having an index based on deleted() be considered indexing effectively using Rushmore (see DG page 400)
>
>Aren't these two very similar in their respective context (i.e.: few discrete values .T. or .F.).
>
>Why should it be OK for deleted() and not for the other(s)?
>
>Thanks
>
>Pierre Richard
Précédent
Répondre
Voir le fil de ce thread
Voir le fil de ce thread à partir de ce message seulement
Voir tous les messages de ce thread
Voir tous les messages de ce thread à partir de ce message seulement