On Tue, May 13, 2025 at 12:49 PM Alena Rybakina <a.rybak...@postgrespro.ru> wrote: > On 12.05.2025 08:30, Amit Kapila wrote: > > On Fri, May 9, 2025 at 5:34 PM Alena Rybakina <a.rybak...@postgrespro.ru> > > wrote: > >> I did a rebase and finished the part with storing statistics separately > >> from the relation statistics - now it is possible to disable the > >> collection of statistics for relationsh using gucs and > >> this allows us to solve the problem with the memory consumed. > >> > > I think this patch is trying to collect data similar to what we do for > > pg_stat_statements for SQL statements. So, can't we follow a similar > > idea such that these additional statistics will be collected once some > > external module like pg_stat_statements is enabled? That module should > > be responsible for accumulating and resetting the data, so we won't > > have this memory consumption issue. > The idea is good, it will require one hook for the pgstat_report_vacuum > function, the extvac_stats_start and extvac_stats_end functions can be > run if the extension is loaded, so as not to add more hooks.
+1 Nice idea of a hook. Given the volume of the patch, it might be a good idea to keep this as an extension. > But I see a problem here with tracking deleted objects for which > statistics are no longer needed. There are two solutions to this and I > don't like both of them, to be honest. > The first way is to add a background process that will go through the > table with saved statistics and check whether the relation or the > database are relevant now or not and if not, then > delete the vacuum statistics information for it. This may be > resource-intensive. The second way is to add hooks for deleting the > database and relationships (functions dropdb, index_drop, > heap_drop_with_catalog). Can we workaround this with object_access_hook? ------ Regards, Alexander Korotkov Supabase
