Re: Reduce the time required for a database recovery from archive.

Hi Dimtry,

On 1/11/21 2:51 AM, Dmitry Shulga wrote:
> Hi Stephen
>
> Based on our last discussion I redesigned the implementation of WAL
> archive recovery speed-up.

Seems like there should have been a patch attached? In any case the
current patch no longer applies so marked Waiting on Author.

Personally, I'm not too keen on this patch as implemented. Several
third-party backup solutions support parallel archive get so it would be
nice to support an interface that simply says to the restore_command,
"go get 1gb of WAL and write the files here." This patch still assumes
that the user has written their own restore command, which is
third-party by definition, so I can't see how interfacing with
third-party software is an issue here.

Also, having multiple workers blindly asking for WAL can cause quite a
bit of traffic and cost because PG knows what WAL it wants but it
doesn't know what exists. On the other hand, a backup solution can
cheaply determine what is available to prevent hammering the archive
with requests for files that don't exist.

Regards,
--
-David
david(at)pgmasters(dot)net