Re: postgres_fdw: Provide better emulation of READ COMMITTED behavior - Mailing list pgsql-hackers

On Thu, Dec 5, 2024 at 4:41 AM Etsuro Fujita <etsuro.fujita@gmail.com> wrote:
> Comments welcome!  Maybe I am missing something, though.

I have a hard time seeing how this would work if cursors are in use on
the main server. Say I do this:

DECLARE foo CURSOR FOR SELECT * FROM ft1 UNION ALL SELECT * FROM ft2;
...fetch some rows from cursor foo but few enough that we only scan ft1...
...do something that causes a snapshot refresh like issue another query...
...fetch more rows from cursor foo until we start scanning ft2...

--
Robert Haas
EDB: http://www.enterprisedb.com