On Thu, Apr 4, 2019 at 2:52 PM Julien Rouhaud <rjuju...@gmail.com> wrote:
> On Thu, Apr 4, 2019 at 1:25 PM Magnus Hagander <mag...@hagander.net> > wrote: > > > > On Thu, Apr 4, 2019 at 10:47 AM Julien Rouhaud <rjuju...@gmail.com> > wrote: > >> > >> Actually we do track counters for shared relations (see > >> pgstat_report_stat), we just don't expose them in any view. But it's > >> still possible to get the counters manually: > >> > >> # select pg_stat_get_db_blocks_hit(0); > >> pg_stat_get_db_blocks_hit > >> --------------------------- > >> 2710329 > >> (1 row) > > > > > > Oh, right, we do actually collect it, we just don't show is. So that's > another argument *for* having it in pg_stat_database. Or at least not for > having it in a checksum specific view, because then we should really make a > separate view for this as well. > > Ok, so let's expose all the shared counters in pg_stat_database and > remove the pg_stat_checksum view. > > >> My main concern is that pg_stat_get_db_numbackends(0) report something > >> like the total number of backend (though it seems that there's an > >> extra connection accounted for, I don't know which process it's), so > >> if we expose it in pg_stat_database, sum(numbackends) won't make sense > >> anymore. > > > > We could also just hardcoded it so that one always shows 0? > > That's a bit hacky, but that's probably the best compromise. Attached > v4 with all those changes. > I'm not sure I like the idea of using "<shared_objects>" as the database name. It's not very likely that somebody would be using that as a name for their database, but i's not impossible. But it also just looks strrange. Wouldn't NULL be a more appropriate choice? Likewise, shouldn't we return NULL as the number of backends for the shared counters, rather than 0? Micro-nit: + <entry>Time at which the last data page checksum failures was detected in s/failures/failure/ -- Magnus Hagander Me: https://www.hagander.net/ <http://www.hagander.net/> Work: https://www.redpill-linpro.com/ <http://www.redpill-linpro.com/>
