On Tue, Jun 7, 2022, at 12:03 AM, Laurenz Albe wrote: > On Sat, 2022-06-04 at 21:18 +0000, Phil Florent wrote: > > I opened an issue with an attached code on oracle_fdw git page : > > https://github.com/laurenz/oracle_fdw/issues/534 > > Basically I expected to obtain a "no privilege" error from PostgreSQL when > > I have no read privilege > > on the postgres foreign table but I obtained an Oracle error instead. > > Laurenz investigated and closed the issue but he suggested perhaps I should > > post that on > > the hackers list since it also occurs with postgres-fdw on some occasion(I > > have investigated some more, > > and postgres_fdw does the same thing when you turn onuse_remote_estimate.). > > Hence I do... > > To add more detais: permissions are checked at query execution time, but if > "use_remote_estimate" > is used, the planner already accesses the remote table, even if the user has > no permissions > on the foreign table. > > I feel that that is no bug, but I'd be curious to know if others disagree. You should expect an error (like in the example) -- probably not at that point. It is behaving accordingly. However, that error is exposing an implementation detail (FDW has to access the remote table at that phase). I don't think that changing the current design (permission check after planning) for FDWs to provide a good UX is worth it. IMO it is up to the FDW author to hide such cases if it doesn't cost much to do it.
-- Euler Taveira EDB https://www.enterprisedb.com/
