Horton

Re: Skipping schema changes in publication

Peter Eisentraut <peter.eisentraut@enterprisedb.com>

View thread
From: Peter Eisentraut <peter.eisentraut@enterprisedb.com>
To: vignesh C <vignesh21@gmail.com>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Date: 2022-05-04T13:34:54Z
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 →

  1. Fix miscellaneous issues in EXCEPT publication clause.

  2. Change syntax of EXCEPT TABLE clause in publication commands.

  3. Add support for EXCEPT TABLE in ALTER PUBLICATION.

  4. Allow table exclusions in publications via EXCEPT TABLE.

  5. Add wait_for_subscription_sync for TAP tests.

On 14.04.22 15:47, Peter Eisentraut wrote:
> That said, I'm not sure this feature is worth the trouble.  If this is 
> useful, what about "whole database except these schemas"?  What about 
> "create this database from this template except these schemas".  This 
> could get out of hand.  I think we should encourage users to group their 
> object the way they want and not offer these complicated negative 
> selection mechanisms.

Another problem in general with this "all except these" way of 
specifying things is that you need to track negative dependencies.

For example, assume you can't add a table to a publication unless it has 
a replica identity.  Now, if you have a publication p1 that says 
includes "all tables except t1", you now have to check p1 whenever a new 
table is created, even though the new table has no direct dependency 
link with p1.  So in more general cases, you would have to check all 
existing objects to see whether their specification is in conflict with 
the new object being created.

Now publications don't actually work that way, so it's not a real 
problem right now, but similar things could work like that.  So I think 
it's worth thinking this through a bit.