Re: Implementing foreign data wrappers and avoiding n+1 querying

On Thu, 22 Dec 2022 at 13:31, David Gilman <davidgilman1@gmail.com> wrote:
>
> When a fdw table participates in query planning and finds itself as
> part of a join it can output a parameterized path. If chosen, Postgres
> will dutifully call the fdw over and over via IterateForeignScan to
> fetch matching tuples. Many fdw extensions do network traffic, though,
> and it would be beneficial to reduce the total number of queries done
> or network connections established.

Sounds like you might be looking for fdw_startup_cost [1].

David

[1] https://www.postgresql.org/docs/current/postgres-fdw.html