On Wed, 2025-12-10 at 15:44 +0300, Alexander Pyhalov wrote:
> There's a long-standing issue with postgres_fdw - as it uses cursors, it
> prefers plans, optimized for fetching first rows. In bad scenarios this
> leads to suboptimal choice of join methods (e.g. choosing nest loop over
> hash join) on remote side. I've crafted WIP patch, which tries to fix
> this issue. It adds FETCH ALL cursors and uses them in postgres_fdw.
> What do you think? Should we go in this direction?
Why not simply set cursor_tuple_fraction to 1.0 in postgres_fdw sessions?
Yours,
Laurenz Albe