Re: row filtering for logical replication

On Tue, Nov 30, 2021 at 2:49 PM tanghy(dot)fnst(at)fujitsu(dot)com
<tanghy(dot)fnst(at)fujitsu(dot)com> wrote:
>
> On Thursday, November 25, 2021 11:22 AM Peter Smith <smithpb2250(at)gmail(dot)com> wrote:
> >
> > Thanks for all the review comments so far! We are endeavouring to keep
> > pace with them.
> >
> > All feedback is being tracked and we will fix and/or reply to everything ASAP.
> >
> > Meanwhile, PSA the latest set of v42* patches.
> >
> > This version was mostly a patch restructuring exercise but it also
> > addresses some minor review comments in passing.
> >
>
> Thanks for your patch.
> I have two comments on the document in 0001 patch.
>
> 1.
> + New row is used and it contains all columns. A <literal>NULL</literal> value
> + causes the expression to evaluate to false; avoid using columns without
>
> I don't quite understand this sentence 'A NULL value causes the expression to evaluate to false'.
> The expression contains NULL value can also return true. Could you be more specific?
>
> For example:
>
> postgres=# select null or true;
> ?column?
> ----------
> t
> (1 row)
>

Updated publication docs in v44 [1].

>
> 2.
> + at all then all other filters become redundant. If the subscriber is a
> + <productname>PostgreSQL</productname> version before 15 then any row filtering
> + is ignored.
>
> If the subscriber is a PostgreSQL version before 15, it seems row filtering will
> be ignored only when copying initial data, the later changes will not be ignored in row
> filtering. Should we make it clear in document?

Updated subscription docs in v44 [1].

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[1] https://www.postgresql.org/message-id/CAHut%2BPtjxzedJPbSZyb9pd72%2BUrGEj6HagQQbCdO0YJvr7OyJg%40mail.gmail.com

Kind Regards,
Peter Smith.
Fujitsu Australia