On Sat, Jan 14, 2012 at 04:41:57AM -0500, Jaime Casanova wrote: > pgstattuple and relation_free_space are very close in all the numbers > except for 2 indexes pgbench_branches_pkey and pgbench_tellers_pkey; > after a VACUUM FULL and a REINDEX (and the difference persistence) i > checked pgbench_tellers_pkey contents (it has only one page besides > the metapage) and the numbers that i look at where: > > page size: 8192 > free size: 4148 > > which in good romance means 50% of free space... so, answering Noah's > question: if that difference has some meaning i can't see it but > looking at the evidence the measure relation_free_space() is giving is > the good one > > so, tomorrow (or ...looking at the clock... later today) i will update > the relation_free_space() patch to accept toast tables and other kind > of indexes and add it to the commitfest unless someone says that my > math is wrong and somehow there is a more accurate way of getting the > free space (which is entirely possible)
Did you see this followup[1]? To summarize: - pgstattuple() and relation_free_space() should emit the same number, even if that means improving pgstattuple() at the same time. - relation_free_space() belongs in the pgstattuple extension, because its role is cheaper access to a single pgstattuple() metric. Thanks, nm [1] http://archives.postgresql.org/message-id/20111218165625.gb6...@tornado.leadboat.com -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
