Re: Reviewing freeze map code

On Tue, Jun 7, 2016 at 2:52 AM, Robert Haas <robertmhaas(at)gmail(dot)com> wrote:
>
> On Mon, Jun 6, 2016 at 5:06 PM, Andres Freund <andres(at)anarazel(dot)de> wrote:
>
>
> > I'd also be ok with adding & documenting (beta release notes)
> > CREATE EXTENSION pg_visibility;
> > SELECT relname FROM pg_class WHERE relkind IN ('r', 'm') AND NOT
pg_check_visibility(oid);
> > or something olong those lines.
>
> That wouldn't be too useful as-written in my book, because it gives
> you no detail on what exactly the problem was. Maybe it could be
> "pg_check_visibility(regclass) RETURNS SETOF tid", where the returned
> TIDs are non-frozen TIDs on frozen pages. Then I think something like
> this would work:
>
> SELECT c.oid, pg_check_visibility(c.oid) FROM pg_class WHERE relkind
> IN ('r', 't', 'm');
>

I have implemented the above function in attached patch. Currently, it
returns SETOF tupleids, but if we want some variant of same, that should
also be possible.

With Regards,
Amit Kapila.
EnterpriseDB: http://www.enterprisedb.com