Re: First-draft release notes for next week's releases

On 03/15/2014 01:02 PM, Tom Lane wrote:
> First-draft release notes are committed, and should be visible at
> http://www.postgresql.org/docs/devel/static/release-9-3-4.html
> once guaibasaurus does its next buildfarm run a few minutes from
> now. Any suggestions?

Hmmm, not sure I like this. It's complicated without being complete,
and supplies just enough information to get someone into trouble:

Also, the error fixed in the second changelog entry below could have
caused some bloat in statistics data. Users who have done many DROP
DATABASE commands since upgrading to 9.3 may wish to manually remove
files in $PGDATA/pg_stat_tmp (or $PGDATA/pg_stat if the server is not
running) that have old modification times and do not correspond to any
database OID present in $PGDATA/base. If you do this, note that the file
db_0.stat is a valid file even though it does not correspond to any
$PGDATA/base subdirectory.

I kind of think that either we should provide complete instructions
(which would be about 3/4 of a page), or provide limited instructions
and assume the only users who will do this are ones who already
understand pg_stat (a reasonable assumption in my opinion), so my
suggestion is move the advice paragraph from E 1.1 to the individual fix
entry in E.1.2, and change it to this:

* Remove the correct per-database statistics file during DROP DATABASE
(Tomas Vondra)

This fix prevents a permanent leak of statistics file space.

Users who have done many DROP DATABASE commands in PostgreSQL 9.3 may
wish to examine their statistics directory for statistics files which do
not correspond to any existing database and delete them. Please note
that db_0.stat is a needed statistics file.

--
Josh Berkus
PostgreSQL Experts Inc.
http://pgexperts.com