> David Blasby <[EMAIL PROTECTED]> writes: >> I just did another vacuum analyse on the table: > > Ah, here we go: > >> INFO: "csn_edges": found 0 removable, 16289929 nonremovable row >> versions in 2783986 pages > > That works out to just under 6 rows per 8K page, which wouldn't be too > bad if the rows are 1K wide on average, but are they? (You might want > to run contrib/pgstattuple to get some exact information about average > tuple size.) > >> INFO: analyzing "public.csn_edges" >> INFO: "csn_edges": 2783986 pages, 3000 rows sampled, 6724 estimated >> total rows > > This looks like a smoking gun to me. The huge underestimate of number > of rows from ANALYZE is a known failure mode of the existing sampling > method when the early pages of the table are thinly populated. (Manfred > just fixed that for 7.5, btw.)
Tom, is there a way choose between a sample and full? > > I think you want to VACUUM FULL or CLUSTER the table, and then take a > look at your FSM settings and routine vacuuming frequency to see if > you need to adjust them to keep this from happening again. > > regards, tom lane > > ---------------------------(end of broadcast)--------------------------- > TIP 5: Have you checked our extensive FAQ? > > http://www.postgresql.org/docs/faqs/FAQ.html > ---------------------------(end of broadcast)--------------------------- TIP 5: Have you checked our extensive FAQ? http://www.postgresql.org/docs/faqs/FAQ.html