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.) 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