Re: Vacuum writes on empty system - Mailing list pgsql-hackers

From Tom Lane
Subject Re: Vacuum writes on empty system
Date
Msg-id 13342.1096655627@sss.pgh.pa.us
Whole thread Raw
In response to Vacuum writes on empty system  ("onion" <onion@taxi.com>)
List pgsql-hackers
"onion" <onion@taxi.com> writes:
> I just loaded up 9GB of data (32 tables) into a brand new system (Postgres
> 7.4.5 on Linux 2.4 with 1GB ram, IDE). I immediately ran "vacuum analyze"
> but Postgres seems to be writing a lot to disk even though none of the
> tables have incurred any UPDATES or DELETES yet and there are no other
> connections or process running. Is it normal for vacuum to be writing to
> disk even when there is nothing to clean up?

Your assumption that there is nothing for VACUUM to do is mistaken.

It's probably setting the known-committed hint bits in all the tuple
headers of the newly loaded data.
        regards, tom lane


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