Re: Bags versus sets; are they needed?
From: <paul.vernon_at_ukk.ibmm.comm>
Date: Tue, 2 Apr 2002 15:30:43 +0100
Message-ID: <a8cg4b$17mc$1_at_sp15at20.hursley.ibm.com>
Date: Tue, 2 Apr 2002 15:30:43 +0100
Message-ID: <a8cg4b$17mc$1_at_sp15at20.hursley.ibm.com>
> I believe that the original motivation for returning bags ("sets" with
> duplicate values retained) was one of performance: to eliminate the
> extra step, that would be required if duplicates were to be removed.
> My question is simple: Do you personally have code, where the
> retaining of duplicate tuples is essential/convenient/whatever? If so
> - could you provide me with an insight in to what problem is solved.
Have a look at C J Date on this subject.
Double Trouble, DOuble Trouble Part1
http://www.dbdebunk.com/cjddtdt.htm
Regards
Paul Vernon
Business Intelligence, IBM Global Services
Received on Tue Apr 02 2002 - 16:30:43 CEST