Roman Rokytskyy wrote:

>>The question is not whether it can be done at the execution time but
>>whether it should be. IIRC, the SQL spec explicitly requires
>>permissions to be checked at the prepare time. And it makes a lot of
>>sense to me.
>>
>>
>
>This fits very well the model where role is specified at connect time.
>However, if we allow to change the role at runtime, we have either to
>invalidate all prepared statements or to check the permissions, etc.
>
>So, _if_ we consider Jim's proposal for implementation, then also
>permission management should be changed.
>
>
>

Checking permissions at prepare time is necessary and should be
sufficient even if the the active role(s) change. I don't see a problem
as long as the rules are clear and documented.