Re: Random slow queries

On Tue, Jun 28, 2016 at 6:24 PM, <devel(dot)brain99(at)xoxy(dot)net> wrote:
>
>
> PostgreSQL version:
> PostgreSQL 9.3.4, compiled by Visual C++ build 1600, 64-bit

The current minor version of that branch is 9.3.13, so you are 9 bug
fix releases behind.

I don't know if this matters, because I see that my first guess of
your problem was fixed in commit 4162a55c77cbb54acb4ac442e, which was
already included in 9.3.4. (Yes, you did say you also observed the
problem in 9.5.3, but still, why intentionally run something that far
behind?)

> Things I tried:
> - Upgrading to PostgreSQL 9.5.3, compiled by Visual C++ build 1800, 64-bit
> This did not solve the problem, queries still take 122 seconds from time to
> time

Could you try 9.6beta2?

In particular, I am wondering if your problem was solved by

commit 8a7d0701814a4e293efad22091d6f6fb441bbe1c
Author: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
Date: Wed Aug 26 18:18:57 2015 -0400

Speed up HeapTupleSatisfiesMVCC() by replacing the XID-in-progress test.

I am not entirely sure why this (as opposed to the previous-mentioned
4162a55c77cbb54) would fix a problem occurring during BIND, though.

Cheers,

Jeff