FreeTDS Development Group

[Steve Willer <willer AT novator.com>]

I'm getting some strange (and frankly scary) results. This is with a
Solaris/Intel client, running FreeTDS 0.52, talking to a Linux/Intel box
running Sybase 11.9.2. I have the client configured for TDS 5.0. The
client is also running the latest DBD::Sybase, through Perl obviously.

If I run a "select * from sometable" query, and then fetch the rows one by
one, at around 200 or 300 retrieved rows, the client starts to freak out.

Here's a relevant excerpt:

READING ROW 411:
READING ROW 412:
Out of memory during ridiculously large request at
modules/VR/Kernel/Database.pm line 1282.
Unknown marker: 44!!
Unknown marker: 114!!
Unknown marker: 101!!
Unknown marker: 109!!
Unknown marker: 105!!
Unknown marker: 110!!
Unknown marker: 100!!
Unknown marker: 95!!
Unknown marker: 109!!
Unknown marker: 101!!
Unknown marker: 115!!
Unknown marker: 115!!
Unknown marker: 97!!
Unknown marker: 103!!


The "READING ROW" line is debug statements of mine in the perl script, as
it calls fetchrow_hashref. As you can tell, it read the rows fine until
just after row 412 in this case, then I get a "ridiculously large
request", and then a huge set of "Unknown marker" warnings that end up
printing out a random spew of what are supposedly marker values.

This only seems to happen with text fields that have, say, at least a
hundred or so characters in the field values. I can't tell if it's text
fields that cause FreeTDS to break, or just large row results.

What I think might be happening is perhaps FreeTDS is getting out of sync
on the TDS stream with the server under some condition. It could be off by
a byte, even, and then might be getting large message lengths, trying to
allocate that huge memory, and then if it survives that, it ends up seeing
markers in places they shouldn't be in.

So....time is running short for me, unfortunately, and I'm getting scared.
Has anyone else seen this? Is there a fix? I'm running the latest FreeTDS,
and I don't see any relevant changes in the CVS copy. Can someone help me
out?