Re: Forcing wal rotation

Ühel kenal päeval, R, 2006-07-14 kell 17:39, kirjutas Simon Riggs:
> On Fri, 2006-07-14 at 12:09 -0400, Tom Lane wrote:
> > "Florian G. Pflug" <fgp(at)phlo(dot)org> writes:
> > > I've now thought about how to fix that without doing that rather crude rsync-pg_xlog-hack.
> > > I've read through the code, and learned that wal-segments are expected to have a specific size -
> > > thus rotating them "early" is not that easy.
> >
> > Simon was working on a patch for this at the code sprint; I think it's
> > submitted to -patches already.
>
> Slightly different patch. I'm working on this one still.

What is your approach here ?

And by any chance, do you plan to backport the standby WAL playback mode
patches to 8.0 and 8.1 series ?

> > Explicitly filling the segment as you
> > propose would be really bad for performance.
>
> Yes, current approach I am taking is better than that.

Another thing that was discussed was adding a function to postgres that
could be called to get current WAL file and offset, so an external
process could do async wal-copying at the time WAL is being written
instead of copying it all when it is finished.

This could reduce the lag of data availability to only (fractions of)
seconds.

Is anyone working on it ?

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