Re: Writeable CTEs Desgin Doc on Wiki

On 2010-08-17 6:41 AM +0300, Hitoshi Harada wrote:
> 2010/8/17 Robert Haas<robertmhaas@gmail.com>:
>> There are really two separate features here, and it might be worth
>> giving them separate names and separate designs (and separate
>> patches).  Allowing the main query to be an insert, update, or delete
>> seems easier than allowing the toplevel CTEs to contain those
>> constructs, although I might be wrong about that.
>>
>> Under features, what is DCL?  There has been previous talk of allowing
>> WITH (COPY ...) and I am personally of the opinion that it would be
>> nice to be able to do WITH (EXPLAIN ...).  DDL seems like a poor idea.
>
> So, there are three? One for allowing the main query to be an insert,
> update, or delete, one for the main subject of writeable CTE with
> insert, update, delete and one for allowing COPY to return rows. I am
> attracted by such COPY functionality.
>
> And the first part seems easier to be committed separately. Is it
> possible to get it in by only adding syntax and little parser/planner
> modification, or more executor code?

It's not that simple, see:
http://archives.postgresql.org/pgsql-hackers/2010-02/msg01065.php


Regards,
Marko Tiikkaja