Level Extreme platform
Subscription
Corporate profile
Products & Services
Support
Legal
Français
SET DELETE ON and SQL
Message
From
17/07/1998 16:46:15
 
 
To
17/07/1998 16:40:26
Jerry Tovar
Dana Corporation Dana It
Maumee, Ohio, United States
General information
Forum:
Visual FoxPro
Category:
Other
Miscellaneous
Thread ID:
00118353
Message ID:
00118808
Views:
13
>>Hi Jerry.
>>
>>
>>FoxPro DOS 2.6
>>set deleted on: 0.08 set deleted off: 0.06
>>not bad.
>>
>>Visual Foxpro 5.0a
>>set deleted on: 3.50 set deleted off: 0.06
>>oh my!
>>
>>Here is the interesting one. I removed the tag on deleted() and deleted 5000 records in the table.
>>Visual Foxpro 5.0a
>>set deleted on: 0.05 set deleted off: 0.04
>>Huh??
>>
>>Anyone have any clues, suggestions, comments, or anything???
>>
>>-Michael M. Emmons
>>
>
>Michael,
>
>Thanks for your reply. Here's a couple of more things I tried.
>
>I copied my table to my hard drive.
>On my drive, DELETED ON is only slightly slower than DELETED OFF. Both are acceptable.
>
>On our Novell Drive and DELETED ON, the query takes 15+ seconds. With DELETED OFF, the query is almost instant.
>
>I do quit out of VFP after each query.
>
>It's really strange. I have not tried removing the DELETED() tag yet. The weird part is that SYS(3054, 1) says that it's using the DELETED() tag to optimize but it takes so much longer with DELETED ON.
>
>Jerryt

VFP is pulling down a bitmap copy of the deleted index tag structure to your
temp directory. Not sure why but it does this the first time a query is run.
That is why it is important to quit VFP after running a query. If the data is
located on the local drive (as opposed to a network drive) there is nothing to
pull down. That is why it returns so much more quickly.

You will see the same slow behavior by simply BROWSEing a large (500K+)
table on the network the first time. To verify, see the constant changing
of the bytes received under the network tab of NT diagnostics. Not sure
why this is true in VFP and not in FPW.
Previous
Next
Reply
Map
View

Click here to load this message in the networking platform