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Opinions sought on database/index corruption

One comment in some specs for a windows replacement for a Clipper app I
developed was that Clipper indexes needed to be recreated
more often than desired. I always included a reindex (in fact a recreate
index from scratch) option in all my Clipper apps, in anticipation of this
problem.

The specs are obviously implying that Access databases should be used without
saying this outright, but my one experience with writing in VB gave me the
impression that entire database corruption is just as big a problem with that
platform (not to mention the shipment and version problems inherent with all
the dlls and vbxs.) The program itself also is apparently not all that stable,
although the client seems to have been prepared to put up with that as they
just restart it. This was a VB3 app for win 3.11 on a win nt network.

I have Apollo, and am currently developing an app with that but have yet to have
one running "in anger". Does anyone have experience with this aspect and have
any suggestions as to the most stable database/index combinations?

Kym Wilson
Graphics and Technical Systems

 

Re:Opinions sought on database/index corruption


In article <31F89451.2...@pacific.net.sg> Mohd Rashid Atan <m...@pacific.net.sg> writes:

Quote
>NTX are not very 'solid'. Generally index will become unstable if :
>1) A dbf with ntx is open without ntx.
>2) A dbf with ntx is open with ntx but sequence of the ntx varies.
>I have a site with 20 users. Indexes are being rebuild only once a week; as a precaution;
>not because of corruption.

I've found that for both dBase and Paradox tables a regular practice of
rebuilding indexes is a good idea.  Although maintained indexes degrade very
well, when a lot of insertion activity is going on there's still a speed
advantage to regenerating indexes periodically.

So what I have clients do as part of their backup procedure each night is to
run a ChimneySweep* script that checks all the tables, rebuilds all the
indexes, and leaves them ready for next-morning.  Performance remains good and
at minimal cost.

/mr/
mi...@sundialservices.com
*http://www.azwebproducts.com/computer/sundial/sundial2.htm

Re:Opinions sought on database/index corruption


On 25 Jul 1996 22:29:04 +0800, g...@perth.DIALix.oz.au (Graphics and

Quote
Technical Systems) wrote:
>One comment in some specs for a windows replacement for a Clipper app I
>developed was that Clipper indexes needed to be recreated
>more often than desired. I always included a reindex (in fact a recreate
>index from scratch) option in all my Clipper apps, in anticipation of this
>problem.

I have heard of problems w/ NTX files and the index problems w/ Apollo
(unconfirmed).. I am using FoxPro files w/ CDX index files w/ no
problems.

Quote

>The specs are obviously implying that Access databases should be used without
>saying this outright, but my one experience with writing in VB gave me the
>impression that entire database corruption is just as big a problem with that
>platform (not to mention the shipment and version problems inherent with all
>the dlls and vbxs.) The program itself also is apparently not all that stable,
>although the client seems to have been prepared to put up with that as they
>just restart it. This was a VB3 app for win 3.11 on a win nt network.

?

Quote
>I have Apollo, and am currently developing an app with that but have yet to have
>one running "in anger". Does anyone have experience with this aspect and have
>any suggestions as to the most stable database/index combinations?

I am running a 65+ concurrent user DOS/FoxPro application in which I
have to re-create the index files nightly due to the high traffic.

I am looking at the Advantage Database Server (w/ Apollo),
that is supposed to emulate Client/Server for DBF files on novell
(I hear NT avail soon).
This is supposed to help eliminate index corruption, but I am in the
middle of a major rewrite from DOS to Windows and don't have a
solid answer yet!

Quote

>Kym Wilson
>Graphics and Technical Systems

________________________
Scott Martin
Kvaerner FSSL, Inc.
smar...@firstnethou.com

Re:Opinions sought on database/index corruption


Hi Kym Wilson
NTX are not very 'solid'. Generally index will become unstable if :
1) A dbf with ntx is open without ntx.
2) A dbf with ntx is open with ntx but sequence of the ntx varies.
I have a site with 20 users. Indexes are being rebuild only once a week; as a precaution;
not because of corruption.

Hope it helps.
Rashid.

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