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

On 2014-06-18 16:15:47 +0530, Pavan Deolasee wrote:
> On Wed, Jun 18, 2014 at 3:40 PM, Andres Freund <andres(at)2ndquadrant(dot)com>
> wrote:
>
> >
> > Won't that significantly regress manually issued CHECKPOINT;s?
> >
> >

> May be if there are large unlogged table(s) which are frequently updated
> between manual checkpoints. I don't know how unlogged tables are being
> currently used to make that call.

I think that's actually one of the major reasons to use unlogged tables.

> We could add another flag and use that while taking system checkpoints.

Don't really have a better idea. CHECKPOINT_FLUSH_ALL?

> 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.

Greetings,

Andres Freund

--
Andres Freund http://www.2ndQuadrant.com/
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