Re: row filtering for logical replication

Stephen Frost <sfrost@snowman.net>

From: Stephen Frost <sfrost@snowman.net>

To: Fabrízio de Royes Mello <fabriziomello@gmail.com>

Cc: petr.jelinek@2ndquadrant.com, Euler Taveira de Oliveira <euler@timbira.com.br>, Pgsql Hackers <pgsql-hackers@postgresql.org>, hironobu@interdb.jp

Date: 2018-11-23T19:03:30Z

Lists: pgsql-hackers

Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →

Release cache tuple when no longer needed
- ed0fbc8e5ac9 15.0 landed
Add some additional tests for row filters in logical replication.
- ceb57afd3ce1 15.0 landed
Fix one of the tests introduced in commit 52e4f0cd47.
- cfb4e209ec15 15.0 landed
Allow specifying row filters for logical replication of tables.
- 52e4f0cd472d 15.0 landed
Move scanint8() to numutils.c
- cfc7191dfea3 15.0 cited
Replace Test::More plans with done_testing
- 549ec201d613 15.0 cited
Reduce relcache access in WAL sender streaming logical changes
- 6ce16088bfed 15.0 cited
Small cleanups related to PUBLICATION framework code
- c9105dd3660f 15.0 cited
Add a view to show the stats of subscription workers.
- 8d74fc96db5f 15.0 cited
Allow publishing the tables of schema.
- 5a2832465fd8 15.0 cited
Doc: improve documentation of CREATE/ALTER SUBSCRIPTION.
- 1882d6cca161 15.0 cited
Add PublicationTable and PublicationRelInfo structs
- 0c6828fa987b 15.0 cited
Remove unused argument "txn" in maybe_send_schema().
- 93d573d86571 15.0 cited
Add prepare API support for streaming transactions in logical replication.
- 63cf61cdeb7b 15.0 cited
Unify PostgresNode's new() and get_new_node() methods
- 201a76183e20 15.0 cited
Use l*_node() family of functions where appropriate
- 2b00db4fb0c7 15.0 cited
Add support for prepared transactions to built-in logical replication.
- a8fd13cab0ba 15.0 cited
Restore the portal-level snapshot after procedure COMMIT/ROLLBACK.
- ef9480509622 11.13 cited
Rename a parse node to be more general
- 91d1f2d30210 14.0 landed
Remove unused column atttypmod from initial tablesync query
- 4ad31bb2ef25 14.0 landed
SEARCH and CYCLE clauses
- 3696a600e229 14.0 cited

Greetings,

* Fabrízio de Royes Mello (fabriziomello@gmail.com) wrote:
> On Fri, Nov 23, 2018 at 4:13 PM Petr Jelinek <petr.jelinek@2ndquadrant.com>
> wrote:
> > > If carefully documented I see no problem with it... we already have an
> > > analogous problem with functional indexes.
> >
> > The difference is that with functional indexes you can recreate the
> > missing object and everything is okay again. With logical replication
> > recreating the object will not help.
> >
> 
> In this case with logical replication you should rsync the object. That is
> the price of misunderstanding / bad use of the new feature.
> 
> As usual, there are no free beer ;-)

There's also certainly no shortage of other ways to break logical
replication, including ways that would also be hard to recover from
today other than doing a full resync.

What that seems to indicate, to me at least, is that it'd be awful nice
to have a way to resync the data which doesn't necessairly involve
transferring all of it over again.

Of course, it'd be nice if we could track those dependencies too,
but that's yet another thing.

In short, I'm not sure that I agree with the idea that we shouldn't
allow this and instead I'd rather we realize it and put the logical
replication into some kind of an error state that requires a resync.

Thanks!

Stephen