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From "Yip Ng" <yipng...@gmail.com>
Subject Re: Functions in GROUP BY expressions? (related to DERBY-883)
Date Wed, 15 Nov 2006 19:12:08 GMT
On 11/15/06, Oystein Grovlen - Sun Norway <Oystein.Grovlen@sun.com> wrote:

>I thought we had established that SIN was non-deterministic.  Are you
> saying that SIN is deterministic in some contexts, but not in others?

If we are talking about the current implementation of Derby, then all user
defined functions and built-ins are non-deterministic.  As explained in
my previous comments, Derby does not have a way to declare user functions
deterministically, so they are all treated in non-deterministic manner
implicitly.

What I was trying to convey was most of the built-in functions in Derby are
*supposed*
to be deterministic (aggregates and SIN, COS, TAN, SUBSTR, etc.) since given
the
same argument(s), they return the same result.  And so far, I have been
using
function determinisim to determine what is allowed in the group by
expression in
general and not limited to Derby.  This is what I would like to describe in
the
group by expression documentation when Derby allows functions to be declared

determinisically in the future.

But for now, from a documentation perspective, the Derby ref manual should
mention
what is allowed in the group by expression in 10.2 due to implementation
restrictions.


Regards,
Yip Ng

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