Re: patch: shared session variables

2012/8/31 Dimitri Fontaine <dimitri(at)2ndquadrant(dot)fr>:
> Pavel Stehule <pavel(dot)stehule(at)gmail(dot)com> writes:
>>> Pavel, you didn't say what you think about the WITH FUNCTION proposal?
>>
>> I don't like it - this proposal is too "lispish" - it is not SQL
>
> We're not doing lambda here, only extending a facility that we rely on
> today. The function would be named, for one. I don't know what you mean
> by SQL being lispish here, and I can't imagine why it would be something
> to avoid.
>
>>> And you didn't say how do you want to turn a utility statement into
>>> something that is able to return a result set.
>>
>> if we support "real" procedures ala sybase procedures (MySQL, MSSQL..)
>> - then we can return result with same mechanism - there are no
>> significant difference between DO and CALL statements - you don't know
>> what will be result type before you call it.
>
> Currently we don't have CALL, and we have DO which is not a query but a
> utility statement. Are you proposing to implement CALL? What would be
> the difference between making DO a query and having CALL?

defacto a CALL statement implementation can solve this issue.

The core of this issue is an impossibility using parameters for
utility statements. CALL and DO are utility statements - and if we
can use parameters for CALL, then we can do it for DO too.

CALL statement starts a predefined batch - inside this batch, you can
do anything - can use COMMIT, ROLLBACK, SELECTs, ... DO is some batch
with immediate start. Sure, there is relative significant between
stored procedures implemented in popular RDBMS and although I don't
like T-SQL too much, I like sybase concept of stored procedures - it
is strong and very useful for maintaining tasks.

Regards

Pavel

>
> Regards,
> --
> Dimitri Fontaine
> http://2ndQuadrant.fr PostgreSQL : Expertise, Formation et Support