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How to migrate VFP prog to C/S ?
Message
De
19/03/1998 03:36:34
Emmanuel Huybrechts
Technimeca International Corp.
Montréal, Québec, Canada
 
Information générale
Forum:
Visual FoxPro
Catégorie:
Classes - VCX
Divers
Thread ID:
00085402
Message ID:
00085572
Vues:
45
>Situation:
>
>You need to retrieve a single record from a table across the network. The table and index file uses 500 Mb of disk space. The record is 10K. With VFP, you must transfer all 500Mb over the network, then perform the lookup. With C/S, you have to request the data, then transfer 10K over the network. A 10K transfer is faster than a 500 Mb transfer.

Foxpro never transfer the whole index!
Ex: Say a 500 Mb Index with 50.000.000 records, field indexed is 10 char.
With a binary search, there will be approximatively 27 search = 27 network access of 10 bytes = 270 bytes !!
This is why a well indexed table is as fast or faster than a C/S solution... at least for searching :)

>
>Did the original creator of this thread not say that he was experiencing slow-downs due to large tables?
>
>Joe
>
>>>Just my two cents: When working with large files on a network, there is no way to get around the performance problems other than going to client/server. Your design could be the best possible, but if the files are large enough, you are in trouble.
>>>
>>>Joe
>>
>>Joe, what does it mean large? You can have millions of records and stellar VFP performance. The real difference is how the data used interactively, i.e. how often users create/edit records.
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