Re: SET ROLE and reserved roles

Hi Stephen,

On 2016/04/14 2:10, Stephen Frost wrote:
>> Amit Langote <Langote_Amit_f8(at)lab(dot)ntt(dot)co(dot)jp <javascript:;>> writes:
>>> I observe this:
>>
>>> postgres=# SET ROLE TO NONE;
>>> SET
>>> postgres=# SET ROLE TO nonexistent;
>>> ERROR: role "nonexistent" does not exist
>>> postgres=# SET ROLE TO pg_signal_backend;
>>> ERROR: invalid value for parameter "role": "pg_signal_backend"
>>
>>> Is that behavior deliberate? Might it be better to handle the case
>>> specially much as setting to "none" works?
>
> I don't think it makes sense to say the role doesn't exist when it does, in
> fact, exist.

Sorry, I didn't mean to say that we should error with "<reserved-role>
does not exist" on such SET ROLE attempts. Like Michael, I was a bit
surprised to find that it output "invalid value for parameter".

So, if consensus emerges that we should indeed disallow SET ROLE
<reserved-role-spec>, I would +1 Michael's proposed GUC_check_err*()-based
patch.

Thanks,
Amit