Plateforme Level Extreme
Abonnement
Profil corporatif
Produits & Services
Support
Légal
English
INDEX TAG on DELETED() ......... HUMBUG
Message
De
16/03/1999 14:31:58
 
 
À
16/03/1999 14:18:01
Walter Meester
HoogkarspelPays-Bas
Information générale
Forum:
Visual FoxPro
Catégorie:
Base de données, Tables, Vues, Index et syntaxe SQL
Divers
Thread ID:
00198031
Message ID:
00198269
Vues:
22
>Jim,
>
>Just make sure you use the nofilter statement in your SQL query.
>
>I did just discover that if you ran a query on one instance of VFP in about 60 secondsm you can run the same query in a fraction of this time in another instance of VFP.
>
>It seems that the buffers of the intermediate resultsets used internally by the SQL-SELECT command are maintained by the OS.
From the VFP language reference:
Include NOFILTER to create a cursor that can be used in subsequent queries. In previous versions of Visual FoxPro, it was necessary to include an extra constant or expression as a filter to create a cursor that could be used in subsequent queries. For example, adding a logical true as a filter expression created a query that could be used in subsequent queries:

SELECT *, .T. FROM customers INTO CURSOR myquery

Including NOFILTER can reduce query performance because a temporary table is created on disk. The temporary table is deleted from disk when the cursor is closed.
In the context of this particular thread, what will be the point of including NOFILTER?
Précédent
Répondre
Fil
Voir

Click here to load this message in the networking platform