Path: dp-news.maxwell.syr.edu!spool.maxwell.syr.edu!drn.maxwell.syr.edu!news.maxwell.syr.edu!feeder2.on.meganewsservers.com!meganewsservers.com!reader1.on.meganewsservers.com!reader1.on.meganewsservers.com!not-for-mail ath: nntpswitch.com Date: Tue, 30 Nov 2004 07:42:22 -0800 From: Tom Hester Organization: The Metadata Company User-Agent: Mozilla Thunderbird 0.7.1 (Windows/20040626) X-Accept-Language: en-us, en MIME-Version: 1.0 Newsgroups: comp.databases.theory Subject: Re: Logical equivalence of simple and complex types under the relational model? References: In-Reply-To: Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Message-ID: <64f07$41ac945d$45033832$23838@msgid.meganewsservers.com> Lines: 21 NNTP-Posting-Host: 216.251.47.166 X-Trace: 1101829213 reader1.on.meganewsservers.com 16676 216.251.47.166:54768 Xref: dp-news.maxwell.syr.edu comp.databases.theory:28706 Rene de Visser wrote: > "Tom Hester" wrote in message > news:f2f74$41abb8de$45033832$19131@msgid.meganewsservers.com... > > I have not seen this interpretation of RM. Do you have a reference? I aways > think of RM as tuples over well formed logical expressions, and then > consider the logical system (in the formal sense) generated. > > > Rene. > This is a common conceptualization of relational databases in what used to be called the field of "logic databsaes". There are many books on the subject in the mid-80's and several contemporary introductions to finite model theory discuss the notion. Model theory treats a language as a syntax, the rules of the language (query language if you prefer) and an interpretation of the language into a model (a data model if you prefer). I did a search on "model theory database" in Goggle and got lots of hits. For a simple intro see: http://isrc.massey.ac.nz/finite_model_theory.html .