On Mon, Sep 7, 2015 at 6:28 AM, Amit Kapila <amit.kapil...@gmail.com> wrote:
> On Sun, Sep 6, 2015 at 5:58 PM, Andres Freund <and...@anarazel.de> wrote: > > > > On 2015-09-04 23:44:21 +0100, Simon Riggs wrote: > > > I see the need for both current wait information and for cumulative > > > historical detail. > > > > > > I'm willing to wait before reviewing this, but not for more than 1 > more CF. > > > > > > Andres, please decide whether we should punt to next CF now, based upon > > > other developments. Thanks > > > > I think we can do some of the work concurrently - the whole lwlock > > infrastructure piece is rather independent and what currently most of > > the arguments are about. I agree that the actual interface will need to > > be coordinated. > > > > Ildus, could you please review Amit & Robert's patch? > > > > Are you talking about patch where I have fixed few issues in Robert's > patch [1] or the original patch [3] written by me. > AFAICS, Andres meant [3]. [1] - > http://www.postgresql.org/message-id/caa4ek1kdec1tm5ya9gkv85vtn4qqsrxzkjru-tu70g_tl1x...@mail.gmail.com > [2] - > http://www.postgresql.org/message-id/3f71da37-a17b-4961-9908-016e6323e...@postgrespro.ru > [3] - > http://www.postgresql.org/message-id/caa4ek1kt2e6xhvigisr5o1ac9nfo0j2wtb8n0ggd1_jklde...@mail.gmail.com > For me, major issues of [3] are: 1) We fit all information about current wait event into single byte. 2) We put this byte into PgBackendStatus. Both of these issues are essential for design of [3]. Issue #1 means that we actually can expose to user only event type (until there are less then 256 types) with no parameters [4]. Issue #2 means that we have to monitor only backend not auxiliary processes [5]. Both of these issues seems to be serious limitations for me. It makes me think we either need a different design or need to expose current wait event in some other way additionally. Anyway, I think attracting more attention to this problem is good. It would be very nice if Simon or Andres give review of this. [4] - http://www.postgresql.org/message-id/CAPpHfdtdF8LyR0zBA_tzAwYq00GFZyVbh_XfFAABRQQ=mbn...@mail.gmail.com [5] - http://www.postgresql.org/message-id/55c3306b.5010...@postgrespro.ru ------ Alexander Korotkov Postgres Professional: http://www.postgrespro.com The Russian Postgres Company
