Re: next value expression

Neil Conway <neilc(at)samurai(dot)com> writes:
> On Wed, 2002-11-27 at 10:29, Manfred Koizar wrote:
>> By accident I stumbled across the following paragraph in the August
>> 2002 draft of SQL 2003:
>>
>> If there are multiple instances of <next value expression>s
>> specifying the same sequence generator within a single
>> SQL-statement, all those instances return the same value for a
>> given row processed by that SQL-statement.
>>
>> Is this of any relevance to PG's nextval()?

> Somewhat -- SQL2003 defines sequence generators that are pretty much
> identical in functionality to PostgreSQL's sequences, although the
> syntax is a bit different.

I would think his point is that the above paragraph specifies behavior
that is very definitely NOT like Postgres'.

> I submitted a patch for 7.4 that adjusts the
> CREATE SEQUENCE grammar to match SQL2003's CREATE SEQUENCE a little more
> closely,

Did we apply it? I'm inclined not to, until we nail down the semantic
implications a little more. Conforming to the spec on syntax when we
don't on semantics strikes me as a bad idea.

regards, tom lane