On Wednesday, February 14, 2024, Adam Fletcher <adamfblahb...@gmail.com> wrote: > > > Is it possible to get the parameterized prepared query inside an FDW such > that it can be prepared/bind'd/execute'd on the receiving end of the FDW? > > For example, if I `PREPARE stmt(int) AS SELECT * from fdwrapped_tbl where > pk = $1;` then `execute stmt(1);` I want my FDW be aware that the query was > prepared. >
That isn’t how the separation of responsibilities works in PostgreSQL. Execute is capable of producing a custom plan where instead of adding in parameters and then planning around those unknowns the newly created plan uses the supplied constants while planning. I do suspect that if a generic plan is chosen you will see the expected parse nodes and can thus build a generic access plan to your foreign server accordingly. You can control this for ease of testing via plan_cache_mode https://www.postgresql.org/docs/current/runtime-config-query.html#GUC-PLAN-CACHE-MODE David J.
