On Thu, 2007-12-13 at 13:52 -0500, Tom Lane wrote: > Alvaro Herrera <alvherre@xxxxxxxxxxxxxx> writes: > > Simon Riggs wrote: > >> We might be able to have bgwriter set hint bits on dirty blocks, > > > I don't think that works, because the bgwriter has no access to the > > catalogs, therefore it cannot examine the page contents. To bgwriter, > > pages are opaque. > > Another issue is that this'd require bgwriter to access the clog SLRU > area. I seem to remember worrying that that could lead to low-level > deadlocks, though I cannot recall the exact case at the moment. > Even without that, it would increase contention for SLRU, which we > probably don't want. I was trying to highlight the problems, not advocate that as an approach, sorry if I wasn't clear enough. Even if you solved the problems both of you have mentioned I don't think the dynamic behaviour will be useful enough to merit the effort of trying. I'm definitely not going to be spending any time on this. Fish are frying elsewhere. -- Simon Riggs 2ndQuadrant http://www.2ndQuadrant.com ---------------------------(end of broadcast)--------------------------- TIP 2: Don't 'kill -9' the postmaster
