On Tue, Feb 10, 2026 at 11:05 AM David G. Johnston < [email protected]> wrote:
> On Tuesday, February 10, 2026, Durgamahesh Manne < > [email protected]> wrote: > >> Hi >> >> I added fillfactor with less than 100 to existing table then ran vacuum >> full to take effect >> >> How to ensure the applied fillfactor is working successfully >> >> A ratio of hot updates in catalog table should higher than value of >> n_dead_tup or n_tup_upd? Or what ? >> >> > While free space on the page is necessary for HOT, it is not sufficient. > > If you want to prove fillfactor isn’t buggy I’d suggest contriving a test > case instead inspecting complex real data. A table with a single bigint > and say 50 fillfactor should be easily visible when inspecting the free > space of a page in the heap (not sure of the exact query for this though). > There is a page-inspect contrib extension that provides low-level details. > What about pgstattuple.free_space and free_percent? -- Death to <Redacted>, and butter sauce. Don't boil me, I'm still alive. <Redacted> lobster!
