Fwd: Re: New 8.4 hot standby feature

On Tuesday 27 January 2009 13:13:32 you wrote:
> On Tue, 2009-01-27 at 12:53 -0500, Gabi Julien wrote:
> > I have merged the last hot standby patch (v9g) to 8.4 devel and I am
> > pleased with the experience. This is promising stuff. Perhaps it is a bit
> > too soon to ask questions here but here it is:
> >
> > 1. Speed of recovery
> >
> > With a archive_timeout of 60 seconds, it can take about 4 minutes before
> > I see the reflected changes in the replica. This is normal since, in
> > addition to the WAL log shipping, it takes more time to do the recovery
> > itself. Still, is there any way besides the archive_timeout config option
> > to speed up the recovery of WAL logs on the hot standby?
>
> Is the recovery itself the bottleneck?

Yes, the logs are shipped every minute but the recevory is 3 or 4 times
longer.

>
> There's a performance improvement submitted here:
> http://archives.postgresql.org/message-id/a778a7260810280033n43f70d36x8c437
>eacf9a5461e(at)mail(dot)gmail(dot)com
>
> But I haven't been following the development of it closely, so you'll
> have to read the thread to see whether it will meet your needs or not.

Thanks I will take a look at it. Also, I came across the record log shipping
feature too in my research:

http://www.postgresql.org/docs/current/static/warm-standby.html#WARM-STANDBY-RECORD

Could this help? If the logs are smaller then I could potentially afford
shipping then at a higher frequency.

>
> Regards,
> Jeff Davis

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