On Wed, 2007-11-14 at 17:46 -0500, Tom Lane wrote: > Russell Smith <mr-russ@xxxxxxxxxx> writes: > > It is possible that analyze is not getting the number of dead rows right? > > Hah, I think you are on to something. ANALYZE is telling the truth > about how many "dead" rows it saw, but its notion of "dead" is "not good > according to SnapshotNow". Thus, rows inserted by a not-yet-committed > transaction would be counted as dead. So if these are background > auto-analyzes being done in parallel with inserting transactions that > run for awhile, seeing a few not-yet-committed rows would be > unsurprising. > > I wonder if that is worth fixing? I'm not especially concerned about > the cosmetic aspect of it, but if we mistakenly launch an autovacuum > on the strength of an inflated estimate of dead rows, that could be > costly. Sounds to me like that could result in autovacuum kicking off while doing large data loads. This sounds suspiciously like problem someone on -novice was having - tripping over a windows autovac bug while doing a data load http://archives.postgresql.org/pgsql-novice/2007-11/msg00025.php -- Brad Nicholson 416-673-4106 Database Administrator, Afilias Canada Corp. ---------------------------(end of broadcast)--------------------------- TIP 3: Have you checked our extensive FAQ? http://www.postgresql.org/docs/faq
