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De
07/09/2006 09:26:52
Suhas Hegde
Dental Surgeon
Sirsi, Inde
 
 
À
07/09/2006 09:15:40
Information générale
Forum:
Visual FoxPro
Catégorie:
Codage, syntaxe et commandes
Titre:
Versions des environnements
Visual FoxPro:
VFP 6 SP5
Divers
Thread ID:
01149759
Message ID:
01151743
Vues:
34
>>>>>
>>>>>An Index caching overload effect ?
>>>>>
>>>>>try, and post this time:
>>>>>
>>>>>use bhav_data
>>>>>SET EXACT ON
>>>>>=lOOKUP(symbol, m.THISVALUE,symbol)
>>>>>SELECT date,open,high,low,close,tottrdqty,sma9,sma12,sma26 FROM bhav_data;
>>>>>where symbol = m.THISVALUE  INTO CURSOR tempDETAIL nofilter
>>>>>
>>>>
>>>>
>>>>Minimum time taken is 9 secs
>>>>
>>>>but if i run the second time with the same value in thisvalue it runs under .5 secs
>>>>
>>>>like
>>>>
>>>>First run with thisvalue = 'ABCD' -- 10 secs
>>>>second run with thisvalue = 'dfsd' -- 10 secs
>>>>third run with thisvalue = 'ABCD' -- .5 secs
>>>>
>>>>that is wilhout cloing the table
>>>
>>>this confirm the caching effect.
>>>
>>>try
>>>
>>>SELECT date,open,high,low,close,tottrdqty,sma9,sma12,sma26 FROM bhav_data;
>>>where symbol = m.THISVALUE AND symbol = symbol INTO CURSOR tempDETAIL nofilter
>>>
>>
>>No the result is the same. the above doesnt make any difference.
>>Can u hilight what u mean by cashing effect ? what is going on ?
>
>VFP load data into an internal cache ( a buffer memory).
>
>try this ( it minimize and clear the buffer, then the execution time is more stable ?):
>
>
>SYS(3050, 1, 1) minimize the buffer size
>
>sys(1104) && unload the buffer
>SELECT .... WHERE .. = m.thisvalue INTO ...
>
No help
same effect
I put the SYS(3050, 1, 1) in init of the form or should i put it before the query ?
sys(1104)
SELECT .... WHERE .. = m.thisvalue INTO
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