On 2015-06-25 10:01:39 -0400, Tom Lane wrote: > Andres Freund <and...@anarazel.de> writes: > > On 2015-06-25 16:26:39 +0530, Amit Kapila wrote: > >> Won't leaving former contents as it is (until the next thing is being > >> blocked) could give misleading information. Currently we mark 'waiting' > >> as false as soon as Heavy Weight Lock is over, so following that way > >> sounds more appropriate, is there any reason why you want it differently > >> than what we are doing currently? > > > But we don't do the same for query, so I don't think that says much. I > > think it'd be useful because it gives you a bit more chance to see what > > you blocked on last, even if the time the backend was blocked was very > > short. > > The problem with the query analogy is that it's possible to tell whether > the query is active or not, by looking at the status column. We need to > avoid a situation where you can't tell if the wait status is current or > merely the last thing waited for.
Well, that's what the 'waiting' column would be about in the proposal I'm commenting about. > At the moment I'm inclined to think we should put this on the back burner > until we see what Ilya submits. None of the proposals for changing > pg_stat_activity sound terribly clean to me. We'll see. To me that's two different things. Knowing what a backend is currently blocked on is a somewhat different use case from keeping longer running stats. E.g. debugging why vacuum is not progressing (waiting for a cleanup lock on a page that needs to be frozen) is just about impossible right now. Greetings, Andres Freund -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
