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Sub queries or separate SELECTs?
Message
 
 
To
23/09/2005 19:07:09
General information
Forum:
Visual FoxPro
Category:
Coding, syntax & commands
Environment versions
Visual FoxPro:
VFP 9
OS:
Windows XP SP2
Network:
Windows XP
Database:
Visual FoxPro
Miscellaneous
Thread ID:
01052615
Message ID:
01052619
Views:
6
James,

The separate sequential queries are ususlly faster. I would first use one query and only split it if its speed became an issue.

>Is there a speed advantage to using separate SELECT commands as opposed to humping them up into a single command using sub queries?
>
>Here's an example of what I'm refering to:
>
>SELECT Field1,CNT(*) as nTotal FROM ATable INTO CURSOR crsCursor1 GROUP BY Field1
>
>SELECT nTotal FROM crsCursor1 INTO CURSOR crsCursor2
>
>
>as opposed to
>
>
>SELECT nTotal FROM (SELECT Field1,CNT(*) as nTotal FROM ATable GROUP BY Field1) INTO CURSOR crsCursor2
>
>
>The first example is more of a pain to clean up after but is easier to debug. I'm just wondering if there is a runtime speed advantage to any of them.
>
--sb--
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