Re: has_column_privilege behavior (was Re: Assert failed in snprintf.c)

Stephen Frost <sfrost(at)snowman(dot)net> writes:
> * Tom Lane (tgl(at)sss(dot)pgh(dot)pa(dot)us) wrote:
>> But it's not quite clear to me what we want the behavior for bad column
>> name to be. A case could be made for either of:
>>
>> * If either the table OID is bad, or the OID is OK but there's no such
>> column, return null.
>>
>> * Return null for bad OID, but if it's OK, continue to throw error
>> for bad column name.
>>
>> The second case seems weirdly inconsistent, but it might actually
>> be the most useful definition. Not detecting a misspelled column
>> name is likely to draw complaints.
>>
>> Thoughts?

> What are we going to do for dropped columns..? Seems like with what
> you're suggesting we'd throw an error, but that'd make querying with
> this function similairly annoying at times.

True, but I think dropping individual columns is much less common
than dropping whole tables.

The general plan in the has_foo_privilege functions is to throw errors for
failing name-based lookups, but return null for failing numerically-based
lookups (object OID or column number). I'm inclined to think we should
stick to that. In the case at hand, we'd be supporting queries that
iterate over pg_attribute, but they'd have to pass attnum not attname
to avoid snapshot-skew failures. That's a bit annoying, but not throwing
error for a typo'ed name is annoying to a different and probably larger
set of users.

regards, tom lane