index corruption dos/clipper harbour/linux - Clipper

Hi Emmer,

> I use several databases (standard dbf/cdx) whom are both used by a clipper
> (5.3) application in a windows environment as well as an harbour(45) on an
> linux slackware environment. The databases are situated on the linux
> machine, and for the clipper app. accessible via samba.

I don't really have a good suggestion to give. However, this is
something I intend to do in the near future, so it's quite important
for me to follow this issue.

>
> Frequently, (but not always) i encounter 'corruption detected' errors. When
> only using the clipper-app, it works fine (in many multi-user sessions).
> The same applies for the harbour app.
>
> In the harbour app, after every UNLOCK id do
> a COMMIT and a __Run("sync;sync;sync;")

Why do you call sync after every commit ? Shouldn't the file system be
left alone working normally ?

>
> Is there a different locking scheme? Am i missing something?
[snip]

I suppose you tested that record locking is honoured, either requested
by clipper or harbour.
>From my experience, on local (win Me) dbf/ntx, a rlock() request made
by harbour is not seen by clipper. The reverse is also true.
Locking appears to work good only when the dbf/ntx is on samba server,
and a SET DBFLOCKSCHEME = 2 is issued at the beginning of the harbour
program . But I don't have an history of continuous use, only sporadic
tests...
Sorry for not beeing able to help,
Regards,
António Vila-Chã
Viana do Castelo
Portugal

Thanks Antonio,

Your remark concering record-lock testing was crucial. I must confess that
I did not actually test record locking being honoured by clipper and
harbour simultaniously.

When I did do a record-lock test, it failed. A record lock in Clipper
DBF/CDX was not honoured by Harbour and vice-versa.

So, I tried "SET DBFLOCKSCHEME=2" but this was a not valid command in
Harbour45. (It is supposed to be valid in xHarbour, but I haven't installed
xHarbour on my system.)

In my DOS/Clipper application I did not link in the CDXLOCK.OBJ. When doing
so, it solved all my problems. Record locking now is honoured by both
dos/clipper & harbour/linux.

Kind regards
Emmer...

Hi Emmer,

[snip]
> So, I tried "SET DBFLOCKSCHEME=2" but this was a not valid command in
> Harbour45. (It is supposed to be valid in xHarbour, but I haven't installed
> xHarbour on my system.)
[snip]

Sorry, it should be "SET DBFLOCKSCHEME TO 2".

Regards,
António Vila-Chã
Viana do Castelo
Portugal