"Spangler, Todd" <ToddSpangler@comsys.com> wrote:
> canceling statement due to user request
> I cannot seem to fix.
Your application is canceling queries, probably because they're not
completing as quickly as it wants them to; that's not a PostgreSQL
bug. You should probably gather a bit more information and post to
the pgsql-performance list, to see what you can do to improve the
query speed.
> I have read that this may have something to do with the Autovacuum
> feature.
Probably not -- at least not directly. It's possible that you
aren't vacuuming aggressively enough, and therefore suffer poor
performance from bloat, but at this point, that's just conjecture.
> It seems the errors do not happen every time.
What pattern is there? Do they come in clusters? Is it particular
queries? Is it particular search arguments for a query?
> If this is the Autovacuum feature, is there a way that I can
> disable this feature and then re-enable it when I am done with the
> creation of my report?
That would probably be counter-productive, although setting
autovacuum cost limits to pace the vacuums might possibly be useful.
> Also, when we receive these errors, it does not save any
> information to the text file like it normally would without the
> error message, so we do not get the report we need when these
> errors occur.
What text file is that? With our configuration, we *do* see
statement text for these in the PostgreSQL log files.
> Another thought would be for us to allow the Autovacuum to be
> turned on only at certain times.
That would be pretty risky, and probably counter-productive.
> I have read that these messages are by design
I'm curious what you read. Can you share a URL?
> I need an easy to use workaround that will allow the reports to
> work. These reports are very important to the company.
Please read these pages and post again to a different list with more
detail:
http://wiki.postgresql.org/wiki/Guide_to_reporting_problems
http://wiki.postgresql.org/wiki/SlowQueryQuestions
In particular, since this could be related to checkpoints, it is
important to have a good description of your hardware, especially
your disk storage system, and all settings in your postgresql.conf
file (excluding all comments).
-Kevin
