Level Extreme platform
Subscription
Corporate profile
Products & Services
Support
Legal
Français
Total of records after delete
Message
From
10/12/2009 13:05:38
 
General information
Forum:
Visual FoxPro
Category:
Coding, syntax & commands
Environment versions
Visual FoxPro:
VFP 9 SP2
OS:
Windows XP SP2
Network:
Windows XP
Database:
Visual FoxPro
Application:
Desktop
Miscellaneous
Thread ID:
01438395
Message ID:
01438447
Views:
28
>>>I would add an index on deleted too
>>>
>>
>>
>>Even after reading this http://fox.wikis.com/wc.dll?Wiki~NonDiscriminatingIndex ?
>
>

Were the tables on a network ? You may be right, though




>I did not read that, but it seems that most of it was written before the binary keyword was added, and then the comments that include it seems to agree there is an advantage (but I just skimmed the text)
>
>Anyways, I just changed the test to have very few records (0.1%) deleted or most of them deleted (99.99%) and run the tests, also added a test to encapsulate the count call on a UDF.
>
>
>
>FUNCTION CountDeletedRecords(tcAlias as String) as Integer
>	LOCAL lnSelect, lcAlias
>	
>	lcAlias			= IIF(VARTYPE(tcAlias) = 'C', m.tcAlias, ALIAS())
>	lnSelect		= SELECT()
>
>	SELECT (m.lcAlias)
>	COUNT TO m.lnRecords
>	SELECT (m.lnSelect)
>	RETURN m.lnRecords
>ENDFUNC
>
>
>The results (granted, not a very scientific test) seems to support the inclusion of the index
>
>
>Records		Index	Time 1	Time 2	Time 3	Time 5
>2958		Yes	0.011	0.001	0.019	0.001
>3095		No	0.451	0.226	0.443	0.226
>2994173		Yes	0.015	0.003	3.980	0.003
>2994026		No	0.796	0.320	3.929	0.317
>
>
>Hugo
Gregory
Previous
Next
Reply
Map
View

Click here to load this message in the networking platform