Re: proposal for 9.5: monitoring lock time for slow queries

2014-08-13 7:19 GMT+02:00 Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>:

> Michael Paquier <michael(dot)paquier(at)gmail(dot)com> writes:
> > Doing a join on pg_stat_activity and pg_locks is not going to help
> > much as you could only get the moment when query has started or its
> > state has changed. Have you thought about the addition of a new column
> > in pg_locks containing the timestamp of the moment a lock has been
> > taken? I am sure that we are concerned about the performance impact
> > that extra calls to gettimeofday could have though...
>
> In theory this could be driven off the same gettimeofday needed to
> start the deadlock_timeout timer. Not sure how messy that'd be.
>

we use it in out custom patch without problems

Pavel

>
> regards, tom lane
>