Re: Surprising dead_tuple_count from pgstattuple - Mailing list pgsql-hackers

From Gordon Shannon
Subject Re: Surprising dead_tuple_count from pgstattuple
Date
Msg-id 1281156191668-2267263.post@n5.nabble.com
Whole thread Raw
In response to Re: Surprising dead_tuple_count from pgstattuple  (Robert Haas <robertmhaas@gmail.com>)
Responses Re: Surprising dead_tuple_count from pgstattuple
List pgsql-hackers

Robert Haas wrote:
> 
> My thought would be "is autovacuum running in the background in
> between these commands?".
> 

That's a good thought, but no, autovacuum_vacuum_scale_factor is set to 0.2,
meaning that over 1 million dead tuples are necessary for autovacuum. 
Besides, if autovacuum had run, I think the pg_stat_user_tables.n_dead_tup
would have reset to zero, as it did after my manual vacuum.

Regarding HOT prune, I never did any updates, so I think there couldn't be
any HOT tuples.  Or does HOT prune do more than that?
-- 
View this message in context:
http://postgresql.1045698.n5.nabble.com/Surprising-dead-tuple-count-from-pgstattuple-tp2266955p2267263.html
Sent from the PostgreSQL - hackers mailing list archive at Nabble.com.


pgsql-hackers by date:

Previous
From: "David E. Wheeler"
Date:
Subject: Re: Initial review of xslt with no limits patch
Next
From: Pavel Stehule
Date:
Subject: Re: Initial review of xslt with no limits patch