Re: CODASYL-like databases

From: David Cressey <cressey73_at_verizon.net>
Date: Thu, 03 Apr 2008 22:16:03 GMT
Message-ID: <DGcJj.641$ta2.250_at_trndny05>


"Rob" <rmpsfdbs_at_gmail.com> wrote in message news:368c0702-da05-428c-9791-ff236dc84d35_at_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. Received on Fri Apr 04 2008 - 00:16:03 CEST

Original text of this message