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Select alltrim(lname) is 10x longer than select lname
Message
De
17/08/2006 12:32:19
Mike Yearwood
Toronto, Ontario, Canada
 
 
À
17/08/2006 12:24:42
Information générale
Forum:
Visual FoxPro
Catégorie:
Codage, syntaxe et commandes
Versions des environnements
Visual FoxPro:
VFP 8 SP1
OS:
Windows XP SP1
Network:
SAMBA Server
Database:
Visual FoxPro
Divers
Thread ID:
01146381
Message ID:
01146452
Vues:
26
>hi mike:
>
>i'll try the populate the combobox and compare times both ways, but that will take me a bit longer to test. will do later today.
>
>however, i don't understand your statement about nofilter. it seems to be saying different things (ie it takes the records from the server and it only does set filter).
>
>let me know. thanks,

Ah, we covered this in the last FoxPro User Group meeting.

Rushmore optimization reads the indexes and doesn't download all the records. In your case VFP is tricking you. It's not downloading all the records, it's just setting a filter. A process that takes very little time.

When you put nofilter, that doesn't happen. The same optimization happens AND the records are copied.

When you then try to operate on that set of records, the SET FILTER way can be slower - like if you put the records in a grid, whereas the NOFILTER way will be fast in a grid.

*IF* a combobox has the same issues as the grid, you will see good speed doing the SELECT, but you may see lousy speed moving in the records - as must happen to populate the combo.
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