Re: posgres 12 bug (partitioned table)

On Tue, Oct 27, 2020 at 10:55 PM Pavel Biryukov <79166341370@yandex.ru> wrote:
>
> Hi!
>
> What's the state with this issue?

I think that the patch that Andres Freund posted earlier on this
thread [1] would be fine as a workaround at least for stable releases
v12 and v13.  I have attached with this email a rebased version of
that patch, although I also made a few changes.  The idea of the patch
is to allocate and use a partition-specific *non-virtual* slot, one
that is capable of providing system columns when the RETURNING
projection needs them.  Andres' patch would allocate such a slot even
if RETURNING contained no system columns, whereas I changed the slot
creation code stanza to also check that RETURNING indeed contains
system columns.  I've attached 2 patch files: one for HEAD and another
for v12 and v13 branches.

That said, the discussion on what to do going forward to *cleanly*
support accessing system columns through partitioned tables is
pending, but maybe the "workaround" fix will be enough in the meantime
(at least v12 and v13 can only get a workaround fix).

--
Amit Langote
EDB: http://www.enterprisedb.com

[1] https://www.postgresql.org/message-id/20200811180629.zx57llliqcmcgfyr%40alap3.anarazel.de