Path: text.usenetserver.com!out02b.usenetserver.com!news.usenetserver.com!in01.usenetserver.com!news.usenetserver.com!newspump.sol.net!newspeer1.nac.net!border2.nntp.dca.giganews.com!nntp.giganews.com!cyclone1.gnilink.net!spamkiller2.gnilink.net!gnilink.net!trndny05.POSTED!3abab865!not-for-mail From: "David Cressey" Newsgroups: comp.databases.theory References: <368c0702-da05-428c-9791-ff236dc84d35@e6g2000prf.googlegroups.com> Subject: Re: CODASYL-like databases Lines: 18 X-Priority: 3 X-MSMail-Priority: Normal X-Newsreader: Microsoft Outlook Express 6.00.2800.1478 x-mimeole: Produced By Microsoft MimeOLE V6.00.2800.1478 Message-ID: Date: Thu, 03 Apr 2008 22:16:03 GMT NNTP-Posting-Host: 72.79.196.12 X-Complaints-To: abuse@verizon.net X-Trace: trndny05 1207260963 72.79.196.12 (Thu, 03 Apr 2008 18:16:03 EDT) NNTP-Posting-Date: Thu, 03 Apr 2008 18:16:03 EDT Bytes: 1825 Xref: usenetserver.com comp.databases.theory:171192 X-Received-Date: Thu, 03 Apr 2008 17:16:05 EST (text.usenetserver.com) "Rob" wrote in message news:368c0702-da05-428c-9791-ff236dc84d35@e6g2000prf.googlegroups.com... > If "The CODASYL network model is much like a persistent representation > of a doubly-linked list", then what does the SET OWNER have to do with > it? What I mean is that it is the relationship between one set owner > and zero or more set members that forms the basis of the model, not > it's implementation as a doubly-linked list with a logical link from > each set member to the set owner. The doubly linked list forms a ring. In that ring are zero, one, or more than one "member records", and exactly one "owner record". Figuring out which record is the owner is mainly a matter of record types, but some implementations make it easier and quicker than that.