>>>>>>>
>>>>>>>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)
>>>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 ?
>
>One time is sufficient
>>sys(1104)
>>SELECT .... WHERE .. = m.thisvalue INTO
>
>Rerun VFP, and post the output of this:
>
>for k=1 to 5
> sys(1104)
> t1=seconds()
> SELECT .... WHERE .. = m.thisvalue INTO
> ? seconds()-m.t1
>next
>
returned
9.838
0.0339
0.0149
0.0149
0.017
