Re: BUG #12834: Avoiding Disk Control Writes for better Laptop / SSD compatibility. pgstats

Bryce Nesbitt wrote:

> Is autovac writing anything of import during its periodic wakeup on an
> idle cluster?

Autovacuum is not writing anything.  What it is doing is asking whether
anyone has written anything -- and the stats collector responds by
writing these stat files.

The issue is that the timestamp-of-last-update bit, which is critical to
autovacuum, does not get written unless the whole file is.  I guess it
is possible to optimize that, so that the file is not touched other than
the timestamp if the database has been completely idle.  I have no idea
how complex this is, or whether this scenario is really worth
optimizing.

--
Álvaro Herrera                http://www.2ndQuadrant.com/
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