Hello I have been using 4.25 build 1, in our the last update of our
applicaiton I updated to 4.25 build 3, now we are having quite a few of
our customers getting corrupt headers in various tables multiple times
in the day. This did not happen in 4.25 build 1. The only things that
changed DB wise is update to build 3 and adding the DBISAM server to
enable large file support.

Any Ideas
Bern

--

Bern,

<< Hello I have been using 4.25 build 1, in our the last update of our
applicaiton I updated to 4.25 build 3, now we are having quite a few of
our customers getting corrupt headers in various tables multiple times in
the day. This did not happen in 4.25 build 1. The only things that
changed DB wise is update to build 3 and adding the DBISAM server to enable
large file support. >>

Are there any applications besides the DBISAM server directly accessing the
database tables ?  If so, then they must *all* be using
LargeFileSupport=True or else you'll get all sorts of corruption because
they won't respect each other's locks.

--
Tim Young
Elevate Software
www.elevatesoft.com

Tim Young [Elevate Software] wrote:

> Bern,
>
> << Hello I have been using 4.25 build 1, in our the last update of
> our applicaiton I updated to 4.25 build 3, now we are having quite a
> few of our customers getting corrupt headers in various tables
> multiple times in the day. This did not happen in 4.25 build 1. The
> only things that changed DB wise is update to build 3 and adding the
> DBISAM server to enable large file support. >>
>
> Are there any applications besides the DBISAM server directly
> accessing the database tables ?  If so, then they must all be using
> LargeFileSupport=True or else you'll get all sorts of corruption
> because they won't respect each other's locks.

Ok That would explain it, I do have 2 services that access the tables
that large file support was not turned on in.

Thanks
Bern

--

Bern Rudisill wrote:

> Tim Young [Elevate Software] wrote:
>
> > Bern,
> >
> > << Hello I have been using 4.25 build 1, in our the last update of
> > our applicaiton I updated to 4.25 build 3, now we are having quite a
> > few of our customers getting corrupt headers in various tables
> > multiple times in the day. This did not happen in 4.25 build 1. The
> > only things that changed DB wise is update to build 3 and adding the
> > DBISAM server to enable large file support. >>
> >
> > Are there any applications besides the DBISAM server directly
> > accessing the database tables ?  If so, then they must all be using
> > LargeFileSupport=True or else you'll get all sorts of corruption
> > because they won't respect each other's locks.
>
> Ok That would explain it, I do have 2 services that access the tables
> that large file support was not turned on in.
>
> Thanks
> Bern

Ok I turned off large file support in my app for the moment and that
has stopped the most of corruption we were getting. But I do have one
table that keeps getting corrupted. This is a read only table and there
is nowhere in my code that writes to the table, any idea why the
headers keep getting corrupt?

Bern

--

Bern,

<< Ok I turned off large file support in my app for the moment and that has
stopped the most of corruption we were getting. But I do have one
table that keeps getting corrupted. This is a read only table and there is
nowhere in my code that writes to the table, any idea why the
headers keep getting corrupt? >>

Something must be writing to it in order to cause a header corrupt error
message.  The header corrupt message is caused by the reader not respecting
the locks of the writer, so that the reader tries to read data (like the
table header) while it is in an inconsistent state.

--
Tim Young
Elevate Software
www.elevatesoft.com

Tim Young [Elevate Software] wrote:

> Bern,
>
> << Ok I turned off large file support in my app for the moment and
> that has stopped the most of corruption we were getting. But I do
> have one table that keeps getting corrupted. This is a read only
> table and there is nowhere in my code that writes to the table, any
> idea why the headers keep getting corrupt? >>
>
> Something must be writing to it in order to cause a header corrupt
> error message.  The header corrupt message is caused by the reader
> not respecting the locks of the writer, so that the reader tries to
> read data (like the table header) while it is in an inconsistent
> state.

I thought of that also, but trust me there is nothing writting to the
table, the only code in my program is a select statement and when I
create the query I set readonly to true. This one has me baffled. Would
a hiccup in network traffic make it look like the header is corrupt?
This is in a file share enviroment by the way not client server.

Bern

--

Bern,

<< I thought of that also, but trust me there is nothing writting to the
table, the only code in my program is a select statement and when I create
the query I set readonly to true. This one has me baffled. Would a hiccup in
network traffic make it look like the header is corrupt? >>

Not normally, no.  Normally network issues show up as OS read or write
errors, not DBISAM-specific errors.

What OS is being used here ?

--
Tim Young
Elevate Software
www.elevatesoft.com

Tim Young [Elevate Software] wrote:

> Bern,
>
> << I thought of that also, but trust me there is nothing writting to
> the table, the only code in my program is a select statement and when
> I create the query I set readonly to true. This one has me baffled.
> Would a hiccup in network traffic make it look like the header is
> corrupt? >>
>
> Not normally, no.  Normally network issues show up as OS read or
> write errors, not DBISAM-specific errors.
>
> What OS is being used here ?

Workstation is Windows XP SP2, server is windows 2000, running in file
share mode.

--

"Bern Rudisill" <bernr@no-sp.am.exitcare dot com> wrote in message
news:69C75E07-156D-4EA5-A0BC-3CAAC10C83C5@news.elevatesoft.com...
>
> Ok I turned off large file support in my app for the moment and that
> has stopped the most of corruption we were getting. But I do have one
> table that keeps getting corrupted. This is a read only table and there
> is nowhere in my code that writes to the table, any idea why the
> headers keep getting corrupt?
>

Does the file date change?

Robert

Robert,

<< Does the file date change? >>

Good question.  I was also going to ask if the LastUpdated timestamp changes
for the table in DBISAM.

--
Tim Young
Elevate Software
www.elevatesoft.com