2010/11/8 Peter Eisentraut <peter_e@gmx.net>:
> On sön, 2010-11-07 at 21:28 +0900, Hitoshi Harada wrote:
>> I've read this Peter's post:
>>
>> http://petereisentraut.blogspot.com/2010/04/news-from-sql-standard.html
>>
>> which says in SQL2011 has a new feature:
>>
>> > Combined data change and retrieval. PostgreSQL does something like this with RETURNING, but this feature is more
elaborateand allows the writing of "delta tables".
>>
>> And I heard from sources that this "delta table" contains something
>> like writeable CTEs. Couldn't you share something about it if
>> possible? I just don't like to design something that will be similar
>> to but different from the standard.
>
> Yeah, actually, after further study, this has nothing to do with actual
> delta tables, and it is in fact exactly the RETURNING feature in
> combination with the possibility to embed it into a superordinate query.
Hmm, this looks very different from our writeable CTEs. And I can see
many issues like syntax ambiguity and execution order if we support
it. AFAIK the most significant reason why we are working on CTEs is
that CTEs are regarded as something like materialized table.
So I think we are going on writeable "CTEs" unless there are no
objection rather than pursuing the standard.
Thanks for sharing anyway.
--
Hitoshi Harada