Re: The job of a relational DBMS
Date: Tue, 01 Dec 2009 19:10:18 -0800
Message-ID: <7embh5ht7v4pv6vttipan4jchitasqf21t_at_4ax.com>
On Tue, 01 Dec 2009 23:44:58 +0100, Thomas Kellerer <OTPXDAJCSJVU_at_spammotel.com> wrote:
>Gene Wirchenko wrote on 01.12.2009 05:35:
>> For example, a group by in SQL forces the result to be sorted by
>> the grouping unless otherwise overridden.
>
>Never has been true. Group by does *not* sort the result.
>Not even in Oracle 8 and and certainly not for any Oracle version > 9
>(and not for any Postgres as well)
It does in my dialect (Visual FoxPro). If you are correct, I overgeneralised.
Granted that that would be implementation-dependent, but it would be convenient for it to do it that way while grouping. (How else would it?) My point is that if the DBMS does any sorting internally, the relational-data-to-app converter should get the benefit of it if it needs it. It would be silly for the DBMS to sort internally and then the converter do it again.
Sincerely,
Gene Wirchenko Received on Tue Dec 01 2009 - 21:10:18 CST