"Jeremy Haile" <jhaile@xxxxxxxxxxx> writes: > Another random idea - does PostgreSQL do any caching of query plans? Only if the client specifies it, either by PREPARE or the equivalent protocol-level message. I dunno what client software you were using, but I think few if any would PREPARE behind your back. Might be worth checking into though, if you've eliminated autovacuum. Actually there's another possibility --- did you create any indexes on the table in between? CREATE INDEX doesn't do a full stats update, but it does count the rows and update pg_class.reltuples. But it's hard to believe that'd have caused as big a rowcount shift as we see here ... regards, tom lane
