Re: how to investigate GIN fast updates and cleanup cycles?

Steve Kehlet <steve(dot)kehlet(at)gmail(dot)com> writes:
> On Fri, Aug 28, 2015 at 10:11 AM Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
>> Hm ... have you tried checking pg_locks to see if they're blocked on
>> something identifiable?

> Yes, I should have mentioned that, I have a cronjob going every minute
> dumping out [blocked/blocking queries](
> https://gist.github.com/skehlet/fbf5f52e18149e14e520) and nothing has shown
> up related to these queries (there were some other normal unrelated
> results, so I believe the job+query itself are working).

BTW, I think your query is probably missing some cases:

( blockingl.transactionid=blockedl.transactionid
OR
(blockingl.relation=blockedl.relation AND blockingl.locktype=blockedl.locktype)
)

This supposes that locks of different strengths don't block each other,
which is certainly wrong. I think you could probably just drop the check
on locktype. You might want to tighten the WHERE to "WHERE
blockingl.granted AND NOT blockedl.granted", as well.

regards, tom lane