Answer is pretty clear, thank you David. On Mon, Aug 16, 2021 at 12:31 AM David Rowley <dgrowle...@gmail.com> wrote:
> On Sun, 15 Aug 2021 at 23:41, otar shavadze <oshava...@gmail.com> wrote: > > SELECT > > (SELECT relpages FROM pg_class where oid = > 'public.my_table'::regclass::oid ) AS table_pages_quantity_total, > > (SELECT COUNT(DISTINCT relblocknumber) FROM pg_buffercache WHERE > relfilenode = ( > > SELECT relfilenode FROM pg_class WHERE oid = > 'public.my_table'::regclass::oid -- (SELECT rel_oid FROM my_cte) > > ) ) AS table_pages_quantity_in_cache; > > > > This shows that table have only one page, while second column shows 3 > unique pages in buffer cache. Seems I'm measuring those numbers > incorrectly(?) can you please help, which column is incorrect (or may be > both) ? > > This question likely is more suited to the pgsql-general mailing list. > My answer in [1] likely will clear this up for you. > > If you need further information, please ask on that thread. > > David > > [1] > https://www.postgresql.org/message-id/caaphdvphddfozoviyxiz2dcr9emrrbnj7n3hks8knsd9w1w...@mail.gmail.com >
