Re: Slow Form Loading Over Network

Tech-Archive recommends: Repair Windows Errors & Optimize Windows Performance

From: Bill Leavy (bleavy_at_optonline.net)
Date: 08/13/04 

Date: Fri, 13 Aug 2004 13:19:30 GMT

Hi Sietse -

I had optimized the queries, that is whyu I was wondering about the
difference in my SYS(3054) results between running the program, and
executing in the command window.

Anyway, deleting the index on DELETED() has solved the problem.

Thanks for your help.

-- Bill

On Fri, 13 Aug 2004 07:24:59 +0200, "Sietse Wijnker"
<sietse.wijnker@ATsw-software.nl> wrote:

>Hi Bill,
>
>Please notice that VFP's dataengine always does the filtering on the local
>machine.
>So when you have a large table that's stored on a network drive and filter
>it with a query, the whole table and it's indexes are downloaded to the
>local machine first, and then queried to retrieve the result-set.
>
>A way to optimize this is using optimized indexes, because when the
>filtercondition is met by an index, only the index is downloaded as a whole,
>the filtering is done over the index nd then the rersultset is downloaded to
>the local macine.
>
>To optimize the queries in the views, you can use the SYS(3054) function.
>Furthermore; there is a chapter in the VFP help about rushmore
>optimalisation:
>http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dv_foxhelp/html/dgusing_rushmore_to_speed_data_access.asp
>
>
>HTH,
>Sietse Wijnker
>
>
>"Bill Leavy" <bleavy@optonline.net> wrote in message
>news:71gnh0lebng9hpnfcrereqakr4dljjg98a@4ax.com...
>> Hi -
>>
>> I have a problem with one of my forms loading very slowly over a
>> network.
>>
>> The app is written in VFP 6 and runs on a Netware network.
>>
>> There are several grids which are populated from parameterized views.
>> The tables that the views are based on contain between 1 and 1.5
>> million records, but the parameterized views contain about 100
>> records.
>>
>> Symantec anti-virus software is loaded on the network, but is set to
>> ignore the directories containing the app and the data.
>>
>> The views are in the data environment and marked "no data on load",
>> and are requeried after the parameter variable is set.
>>
>> The form loads instantly on a standalone machine, and loads instantly
>> over the network if I replace the large tables with smaller tables of
>> the same structure, so it is the combination of the table size and the
>> network that is killing me.
>>
>> The delay appears to be at the point that the views load.
>>
>> The views are fairly simple views, and are created in the view
>> designer of the project manager (not on the fly with code).
>>
>> There is an index tag on deleted().
>>
>> One very curious thing that I noticed is that if I turn on SYS(3054)
>> and run the program, the four views that load all show as partially
>> optimized using the tag on DELETED().
>>
>> If I pull the SQL code out of the view designer though, and run it in
>> the command window, it shows as fully optimized using both the tag on
>> DELETED() and the tag on the primary key ESTID.
>>
>> Here is the SQL code...
>>
>> SELECT *;
>> FROM wizard!wizdat;
>> WHERE Wizdat.estid = ?lcEstID
>>
>>
>> Can anyone tell me why it doesn't run fully optimized from inside the
>> program?
>>
>> Any other ideas on what might be causing the slow loading of the form
>> over the network?
>>
>> I should mention that subsequent loads of the form happen a bit
>> quicker.
>>
>> Any suggestions to speed up the initial load?
>>
>> Thanks to any that can help.
>>
>> -- Bill
>>
>>
>

Relevant Pages

  • Re: Slow Form Loading Over Network
    ... Deleting the DELETEDtag has appeared to solve the problem. ... >> The app is written in VFP 6 and runs on a Netware network. ... >> The form loads instantly on a standalone machine, ...
    (microsoft.public.fox.programmer.exchange)
  • Re: Problem browsing large file
    ... some queries return in a fraction of a second, ... the decision to create the tag on DELETED. ... > Then all that time was consumed pulling the index across the network. ... > If there are no deleted records in the table then you can SET DELETED OFF ...
    (microsoft.public.fox.programmer.exchange)
  • Re: Slow Form Loading Over Network
    ... > The app is written in VFP 6 and runs on a Netware network. ... > The form loads instantly on a standalone machine, ... > optimized using the tag on DELETED. ... > Any other ideas on what might be causing the slow loading of the form ...
    (microsoft.public.fox.programmer.exchange)
  • Re: Slow Form Loading Over Network
    ... Please notice that VFP's dataengine always does the filtering on the local ... So when you have a large table that's stored on a network drive and filter ... > The form loads instantly on a standalone machine, ... > optimized using the tag on DELETED. ...
    (microsoft.public.fox.programmer.exchange)
  • Re: Local tables or linked local database?
    ... How good of a job does Access do mitigating the amount of ... You have used passthrough queries. ... network load - with a network full of people sending emails, printing, ... My posts come from my experience. ...
    (comp.databases.ms-access)