On 11/14/17 11:14, Tom Lane wrote:
>> The common functionality between functions and procedures is like 98%
>> [citation needed], so they definitely belong there, even more so than
>> aggregates, for example.
> No, I don't think so. The core reason why not is that in
>
> SELECT foo(...) FROM ...
>
> foo() might be either a plain function or an aggregate, so it's important
> that functions and aggregates share the same namespace. *That* is why
> they are in the same catalog. On the other hand, since the above syntax
> is not usable to call a SQL procedure, putting SQL procedures into pg_proc
> just creates namespacing conflicts. Do we really want the existence of
> a function foo(int) to mean that you can't create a SQL procedure named
> foo and taking one int argument?
Yes, that is defined that way by the SQL standard.
The point about the overlap refers more to the internals. The entire
parsing, look-up, type-resolution, DDL handling, and other things are
the same.
So for both of these reasons I think it's appropriate to use the same
catalog.
--
Peter Eisentraut http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
