Thanks so much Tom! *Will J. Dunn* *willjdunn.com <http://willjdunn.com>*
On Wed, Jun 17, 2015 at 3:48 PM, Tom Lane <t...@sss.pgh.pa.us> wrote: > William Dunn <dunn...@gmail.com> writes: > > Does anyone which is a more accurate estimate of a table's live > > rows: pg_class.reltuples ( > > http://www.postgresql.org/docs/current/static/catalog-pg-class.html) > > OR pg_stat_all_tables.n_live_tup ( > > > http://www.postgresql.org/docs/current/static/monitoring-stats.html#PG-STAT-ALL-TABLES-VIEW > )? > > They're both inaccurate with different sources of inaccuracy. I dunno > that you should assume that one is necessarily better than the other. > > > - Is pg_class.reltuples an estimation of live tuples only, or is it of > > all tuples (both live and dead)? I would guess it's live only but > that is a > > guess > > Hm. I'm pretty sure the planner takes it as counting live tuples only, > but it looks like VACUUM thinks it includes recently-dead-but-not-yet- > removable tuples. We might need to do some adjustment there. > > regards, tom lane >
