Re: BUG #10675: alter database set tablespace and unlogged table

Andres Freund <andres@2ndquadrant.com> writes:
> On 2014-06-18 16:15:47 +0530, Pavan Deolasee wrote:
>> But I wonder if not flushing dirty buffers
>> of unlogged tables at a checkpoint is a bad idea anyways. User might expect
>> that the unlogged tables to sustain server crash or unclean shutdown if
>> there had been no writes after successful manual checkpoint(s).

> They'll get reset at unlcean startup anyway. Independent of having been
> touched or not.

I'm with Pavan on this one: it's *not* a good thing that manually issued
checkpoints skip unlogged tables.  That's surprising, possibly dangerous,
and no case whatsoever has been made that anyone sees it as an important
performance benefit.

I trust that a shutdown checkpoint, at least, would write such pages?
If so, I'd expect that a manual checkpoint would do it too.  Maybe
I'm checkpointing because I want to be sure that the shutdown will be
quick so I can do a minor release update with minimal downtime.

I think we should just change this.  -1 for new flags and more
complication.

            regards, tom lane