Re: row filtering for logical replication

2018-02-28 21:47 GMT-03:00 David Fetter <david(at)fetter(dot)org>:
> I noticed that the WHERE clause applies to all tables in the
> publication. Is that actually the right thing? I'm thinking of a
> case where we have foo(id, ...) and bar(foo_id, ....). To slice that
> correctly, we'd want to do the ids in the foo table and the foo_ids in
> the bar table. In the system as written, that would entail, at least
> potentially, writing a lot of publications by hand.
>
I didn't make it clear in my previous email and I think you misread
the attached docs. Each table can have an optional WHERE clause. I'll
made it clear when I rewrite the tests. Something like:

CREATE PUBLICATION tap_pub FOR TABLE tab_rowfilter_1 WHERE (a > 1000
AND b <> 'filtered'), tab_rowfilter_2 WHERE (c % 2 = 0),
tab_rowfilter_3;

Such syntax will not block another future feature that will publish
only few columns of the table.

> I also noticed that in psql, \dRp+ doesn't show the WHERE clause,
> which it probably should.
>
Yea, it could be added be I'm afraid of such long WHERE clauses.

> Does it need regression tests?
>
I included some tests just to demonstrate the feature but I'm planning
to add a separate test file for it.

--
Euler Taveira Timbira -
http://www.timbira.com.br/
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