Re: Random slow queries

On 29 June 2016 at 22:20, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
> Don't know if it would be practical for you at all, but if you could
> attach to a process that's stuck like this with a debugger and get a stack
> trace, that would probably be very informative.

It seems I have found the cause of my issues: my antivirus software.
When I tried to debug a stuck process, the currently executing code was in
some DLL without debugging information etc. When checking where the DLL came
from, it appeared to be from the security software I had installed.

I had been meaning to change because I have had some performance issues in
the past (nowhere near as bad as this issue though!) but hadn't yet gotten
around to it. After switching this weekend, the issue went away completely.

Even though I had previously noticed some performance issues with my
antivirus, I must say this still is a very weird failure mode - especially
as it still occurred if I disabled all realtime protection (one of the
first things I tried, even if not mentioned in my earlier emails).

Thanks for the time spent trying to help!

Best regards,
Roel