Re: pgsql: Make the pg_stat_activity view call a SRF

Bruce Momjian <bruce@momjian.us> writes:
> Magnus Hagander wrote:
>> Bruce Momjian wrote:
>>> * Fix system views like pg_stat_all_tables to use set-returning
>>> functions, rather than views of per-column functions
>>
>> Thanks, and while I approve of that TODO, that's not actually the one I
>> was talking about in the email. The one I was talking about was "change
>> builtin set-returning functions to use OUT parameters so you can query
>> them without knowing the result format" or something like that.
>>
>> So, please keep the one you added, but add this one as well.

> Uh, I need more details on this.  Can you give an example?

Good:

regression=# select * from pg_get_keywords();
       word        | catcode |        catdesc
-------------------+---------+-----------------------
 abort             | U       | Unreserved
 absolute          | U       | Unreserved
 access            | U       | Unreserved
 ...

Not so good:

regression=# select * from pg_show_all_settings();
ERROR:  a column definition list is required for functions returning "record"

There's no longer any very good reason for built-in SRFs to not define
their own output record type.

            regards, tom lane