On Mon, May 8, 2017 at 3:48 AM, Craig Ringer <craig.rin...@2ndquadrant.com> wrote:
> Sounds like you're reimplementing pglogical > (http://2ndquadrant.com/pglogical) on top of a json protocol. The fact the protocol is JSON is more a detail, but it's a good start as it's human-readable. > [...] > I have no reason to object to your doing it yourself, and you're welcome to > use pglogical as a reference for how to do things (see the license). It just > seems like a waste. Logical Replication, for the first time, offers a way to implement a replication solution that is not several layers away from the database. Or even: for the first time is something I understand. Using the logical replication we can perform some manipulation of the data I will want to use (tables not necessarily in the same places, schemas not necessarily matching). In particular one not-really-minor annoyance of the current system is that adding a column of the master regularly breaks the replica, and pglogical doesn't resolve this problem. We currently use certain features of Londiste (tables living in different schemas, slightly different data types with the same textual representation, extra columns on the slave...) that are against pglogical requirements, but which can be implemented no problem is a customised replication solution built on top of streaming replication. All in all I'm more thrilled by the idea of having a database throwing a stream of changes at me in a format I can reinterpret, allowing me to write in a target database with a high degree of configurability in the middle (i.e. I just have a Python script receiving the data, munging them and then performing queries), then a complete but schema-rigid replication solution. -- Daniele -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
