Re: [GENERAL] Unable to get postgres running after long time no vacuum

"Leon Mergen" <leon@solatis.com> writes:
>> Perhaps you are not shutting down the standalone mode cleanly after
>> the vacuum?

> Okay, that was obviously it -- I didn't realize I needed to send a
> crtl+D signal to the server when in single user mode to shut it down,
> and figured that any uncommitted changes would be replayed when the
> database was started.

Most of them would be, but the one you actually needed here (the update
of pg_database.datfrozenxid) is treated as a non-WAL-logged action in
pre-8.2 releases :-( ... so you had to have a checkpoint to ensure it
got out to disk.

It's actually not that easy to get out of the single-user mode without
it doing a checkpoint.  I suppose you must have either SIGQUIT or
SIGKILL'd it.  While there's nothing we can do about SIGKILL, it strikes
me that it might be a good safety measure if single-user mode treated
SIGQUIT the same as SIGTERM, ie, non-panic shutdown.  Comments anyone?
        regards, tom lane