Re: "stored procedures"

On 9 May 2011 20:52, Merlin Moncure <mmoncure@gmail.com> wrote:
> On Mon, May 9, 2011 at 1:41 PM, Bruce Momjian <bruce@momjian.us> wrote:
>> Josh Berkus wrote:
>>> Peter,
>>>
>>> > I would like to collect some specs on this feature.  So does anyone have
>>> > links to documentation of existing implementations, or their own spec
>>> > writeup?  A lot of people appear to have a very clear idea of this
>>> > concept in their own head, so let's start collecting those.
>>>
>>> Delta between SPs and Functions for PostgreSQL:
>>>
>>> * SPs are executed using CALL or EXECUTE, and not SELECT.
>>>
>>> * SPs do not return a value
>>> ** optional: SPs *may* have OUT parameters.
>>
>> [ Late reply.]
>>
>> What is it about stored procedures that would require it not to return a
>> value or use CALL?  I am trying to understand what part of this is
>> "procedures" (doesn't return a values, we decided there isn't much value
>> for that syntax vs. functions), and anonymous transactions.
>
> FWICT the sql standard.  The only summary of standard behaviors I can
> find outside of the standard itself is here:
> http://farrago.sourceforge.net/design/UserDefinedTypesAndRoutines.html.
>  Peter's synopsis of how the standard works is murky at best and
> competing implementations are all over the place...SQL server's
> 'CALL'  feature is basically what I personally would like to see. It
> would complement our functions nicely.
>
> Procedures return values and are invoked with CALL.  Functions return
> values and are in-query callable.
>
> The fact that 'CALL' is not allowed inside a query seems to make it
> pretty darn convenient to make the additional distinction of allowing
> transactional control statements there and not in functions.  You
> don't *have* to allow transactional control statements and could offer
> this feature as an essentially syntax sugar enhancement, but then run
> the risk of boxing yourself out of a useful properties of this feature
> later on because of backwards compatibility issues (in particular, the
> assumption that your are in a running transaction in the procedure
> body).

I've seen no mention of SQL/PSM.  Isn't all of this covered by that?

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