Re: 4 the FAQ: Are Commercial DBMS Truly Relational?
From: Marshall Spight <mspight_at_dnai.com>
Date: Mon, 11 Oct 2004 02:32:34 GMT
Message-ID: <6hmad.235847$3l3.143944_at_attbi_s03>
Date: Mon, 11 Oct 2004 02:32:34 GMT
Message-ID: <6hmad.235847$3l3.143944_at_attbi_s03>
"Laconic2" <laconic2_at_comcast.net> wrote in message news:GoadnX8cvMul6vTcRVn-iw_at_comcast.com...
>
> "Marshall Spight" <mspight_at_dnai.com> wrote in message
> news:xMcad.156343$wV.96061_at_attbi_s54...
>
> Two points: first, the empty set carries the same kind of information that
> a NULL in anouter join does, without being a NULL.
Exactly!!!
> Second, in order to accept the result as a relation, you have to allow
> domains that are relations. Since Date does this, it's consistent with the
> direction he's going in.
>
> It looks interesting. Thanks for clearing it up.
My pleasure.
Marshall Received on Mon Oct 11 2004 - 04:32:34 CEST