If I understood correctly, above documentation means, that if FDW have DMLPushdown APIs that is enough. But in reality thats not the case, we need ExecForeignInsert, ExecForeignUpdate, or ExecForeignDelete in case DML is not pushable.
And here fact is DMLPushdown APIs are optional for FDW, so that if FDW don't have DMLPushdown APIs they can still very well perform the DML operations using ExecForeignInsert, ExecForeignUpdate, or ExecForeignDelete.
I agree with you. I guess I was wrong. sorry.
So documentation should be like:
If the IsForeignRelUpdatable pointer is set to NULL, foreign tables are assumed to be insertable, updatable, or deletable if the FDW provides ExecForeignInsert, ExecForeignUpdate, or ExecForeignDelete respectively,
If FDW provides DMLPushdown APIs and the DML are pushable to the foreign server, then FDW still needs ExecForeignInsert, ExecForeignUpdate, or ExecForeignDelete for the non-pushable DML operation.
What's your opinion ?
I agree that we should add this to the documentation, too.
BTW, if I understand correctly, I think we should also modify relation_is_updatabale() accordingly. Am I right?
