Re: Joining data tables and system tables
Date: 6 Jan 2003 07:01:51 -0800
Message-ID: <51d64140.0301060701.2bc73ad8_at_posting.google.com>
mikharakiri_at_yahoo.com (Mikito Harakiri) wrote in message news:<bdf69bdf.0301041032.4164ad44_at_posting.google.com>...
> Catalog table TABLES contain relations as tuples. There is no
> self-referential problem here.
This is another interesting thing: the "table" attribute of the
catalog table isn't relation-valued, but rather contains strings that
"point" to the actual relation. I've just been reading Date & Darwen's
"Third Manifesto" and according to this, pointers are a definite no-no
in a relational database.
Are the tables names in the system catalog really pointers? I'm
wondering if it doesn't matter because the the DBMS itself doesn't
follow the pointers but leaves it up to the database user to do it
manually. I guess also this (manual following of pointers) is the
reason why my original query isn't possible.
Paul. Received on Mon Jan 06 2003 - 16:01:51 CET