On 07/06/10 10:29, John T. Dow wrote: > One of my clients is getting this problem occasionally. Actually, we > can cause it to happen quite reliably by pasting certain text into a > couple of fields, but the vast majority of text entered into the vast > majority of fields causes no problem. > I've read enough to suggest that AV software might be the culprit. > It has been said that it is not sufficient to exclude the database > directory nor even to disable to AV protection, it has to be removed. Depends on the AV software. That advice is general, and is given because _some_ antivirus software is badly written and fails to properly exclude Pg. Some AV software probably behaves fine. > The problem is, their database server is also a file server. As a file server it must have AV protection. The server is running Windows Server 2003 I believe. It has RAID etc. My client's antivirus software is AVG (paid, not free). I would not trust AVG. I've been most unimpressed with it lately - their resident scanning module is immature, incredibly slow, and seems prone to false positives. > Question: Is AV software still regarded as the likely culprit? Likely enough - especially for intermittent issues - that the best thing to do is uninstall it, reboot, and re-test to see if the issue remains. If you can reproduce it without the AV software then it's worth investigating further. > Question: If so, is any particular brand less likely to cause problems, more likely? While I can't speak for Pg here (I don't use Pg on any machine with antivirus, and in fact don't use it in production on Windows at all) my limited experience with AV on Windows has been "the bigger the better". The antivirus modules from Symantec and McAfee seem to be the least evil. Not good, just less evil. In my experience supporting end users, at least, it's VERY, VERY important never to install any "Internet Security" suite if you want the computer to actually work, though. AV vendor firewall packages etc are frickin' poison. Just the basic AV package seems to be OK, though again I can't speak re Pg because I don't use Pg with AV. I'm almost tempted to try tracking down some of these AV-related issues. Unfortunately, though, AV software is not only lacking source code or even .pdb debug symbol files, but tends to be designed to make it hard to debug as part of its tamper resistance. So it's a nightmare to trace. Add the fact that many of the issues reported seem to be races or bugs in the AV file access hooks, and it quickly ceases being worth the pain. It'd be interesting if someone with a paid contract for AV support would go to their AV vendor and get them involved. With the active co-operation of an AV vendor or two and a reproducible fault, some progress might be possible. > I'd had to tell my client to purchase more hardware because the > database software I've recommended has a problem. I have a number of > other clients using Postgres and nobody else has had any problem. > Switching AV software wouldn't be such an issue. First, I'd uninstall it, reboot, re-test to see if you can reproduce the fault. If you still can, it's probably not AVG. If you find the fault goes away when AVG does, try something else like McAfee or Symantec's AV component and see how you go. -- Craig Ringer -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
