Re: Bidirectional Binary Self-Joins
From: Bob Badour <bbadour_at_pei.sympatico.ca>
Date: Sat, 31 Mar 2007 11:45:14 GMT
Message-ID: <eRrPh.17635$PV3.182086_at_ursa-nb00s0.nbnet.nb.ca>
Date: Sat, 31 Mar 2007 11:45:14 GMT
Message-ID: <eRrPh.17635$PV3.182086_at_ursa-nb00s0.nbnet.nb.ca>
Marshall wrote:
> On Mar 30, 12:04 pm, Bob Badour <bbad..._at_pei.sympatico.ca> wrote:
>
>>It would use the equality operation to detect the duplicate. What's more
>>disturbing is it would allow the following without complaint:
>>
>>{ date=12-Dec, teamscores={(team=Calvin, score=31), (team=Hope, score=59) }}
>
> Whether it complained or not would depend on the keys and other
> constraints.
Other constraints maybe... keys absolutely not.
> In another subthread I proposed the following key:
>
> (date, π_team(teamscores))
>
> Isn't that a kick?
Since when is π_team(teamscores) an attribute of the relation? Received on Sat Mar 31 2007 - 13:45:14 CEST