Re: Core team statement on replication in PostgreSQL

Josh Berkus wrote:
> Marko,
>
> > But Tom's mail gave me impression core wants to wait until we get "perfect"
> > read-only slave implementation so we wait with it until 8.6, which does
> > not seem sensible. If we can do slightly inefficient (but simple)
> > implementation
> > right now, I see no reason to reject it, we can always improve it later.
>
> That's incorrect. We're looking for a workable solution. If we could
> get one for 8.4, that would be brilliant but we think it's going to be
> harder than that.
>
> Publishing the XIDs back to the master is one possibility. We also
> looked at using "spillover segments" for vacuumed rows, but that seemed
> even less viable.
>
> I'm also thinking, for *async replication*, that we could simply halt
> replication on the slave whenever a transaction passes minxid on the
> master. However, the main focus will be on synchrounous hot standby.

Another idea I discussed with Tom is having the slave _delay_ applying
WAL files until all slave snapshots are ready.

--
Bruce Momjian <bruce(at)momjian(dot)us> http://momjian.us
EnterpriseDB http://enterprisedb.com

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