On Tue, 21 Jan 2020 at 01:38, Tomas Vondra <tomas.von...@2ndquadrant.com> wrote: > > On Mon, Jan 20, 2020 at 01:04:33AM +0000, tsunakawa.ta...@fujitsu.com wrote: > >From: Tomas Vondra <tomas.von...@2ndquadrant.com> > >> One of the stats I occasionally wanted to know are stats for the SLRU > >> stats (we have couple of those - clog, subtrans, ...). So here is a WIP > >> version of a patch adding that.
+1 > > > >How can users take advantage of this information? I think we also need > >the ability to set the size of SLRU buffers. (I want to be freed from > >the concern about the buffer shortage by setting the buffer size to its > >maximum. For example, CLOG would be only 1 GB.) > > > > You're right the users can't really take advantage of this - my primary > motivation was providing a feedback for devs, benchmarking etc. That > might have been done with DEBUG messages or something, but this seems > more convenient. I've not tested the performance impact but perhaps we might want to disable these counter by default and controlled by a GUC. And similar to buffer statistics it might be better to inline pgstat_count_slru_page_xxx function for better performance. Regards, -- Masahiko Sawada http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
