Re: Feature Request - DDL deployment with logical replication

On Fri, Mar 30, 2018 at 10:16 AM, Peter Eisentraut <peter.eisentraut@2ndquadrant.com> wrote:

On 3/29/18 13:21, Jeremy Finzel wrote:
> Although we are thrilled with some of the features already in logical
> replication, this missing feature is the #1 reason that we don't plan to
> take a serious look at built-in logical replication even for pg11,
> because we have been able to use pglogical with our own extension
> pgl_ddl_deploy in order to broadly deploy logical replication without
> serious overhauls to our SDLC process, having schema changes managed
> well.  We really want a mechanism to put through DDL changes at the same
> transactional point on the subscribers as we do on the publishers, which
> also answers any complexities around deploying master-first or
> slave-first in some interesting cases.
>
> Is there any particular vision for how the community might address this
> need in the future?

I think nobody has completely figured this out yet.  Whatever is in
pglogical and bdr and similar external projects are the best current
compromises.  But they have lots of problems, so I don't know if anyone
is ready to propose something for in core yet.

IMO, it would be an acceptable and good first step to provide a function that will replicate a SQL command through the replication stream at the right point, even if there is still no automation around it.