Re: register/unregister standby Re: Synchronous replication

On 30 August 2010 13:14, Fujii Masao <masao.fujii@gmail.com> wrote:
> I think that the advantage of registering standbys is that we can
> specify which WAL files the master has to keep for the upcoming
> standby. IMO, it's usually called together with pg_start_backup
> as follows:
>
>    SELECT register_standby('foo', pg_start_backup())
>
> This requests the master keep to all the WAL files following the
> backup starting location which pg_start_backup returns. Now we
> can do that by using wal_keep_segments, but it's not easy to set
> because it's difficult to predict how many WAL files the standby
> will require.

+1  I don't like the idea of having to guess how many WAL files you
think you'll need to keep around.

And if these standby instances have to register, could there be a view
to list subscriber information?

--
Thom Brown
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