Plateforme Level Extreme
Abonnement
Profil corporatif
Produits & Services
Support
Légal
English
Search
Message
 
 
À
10/07/2008 06:29:50
Information générale
Forum:
Visual FoxPro
Catégorie:
Base de données, Tables, Vues, Index et syntaxe SQL
Titre:
Re: Search
Versions des environnements
Visual FoxPro:
VFP 9
OS:
Windows XP
Database:
Visual FoxPro
Divers
Thread ID:
01330151
Message ID:
01330158
Vues:
25
Tore,

The original queries are slow because they are not optimizable. As result all records in the table have to be read by the query. That's the primary reason for slowdown.

>
>please read this, I have written it a zillion times: You must NEVER, NEVER, NEVER us ANY reference to ANY object within a select statement!!!!!!!!!!!!!!!!!!!! The reason is that if you do, the search engine must evaluate this expression FOR EVERY RECORD in your table, in this case 6000000 items. This is the primary reason why this is slow!
>
<snip>
--sb--
Précédent
Suivant
Répondre
Fil
Voir

Click here to load this message in the networking platform