Comments on: Tom Kyte on constraints http://www.dbms2.com/2006/02/05/tom-kyte-on-constraints/ Choices in data management and analysis Wed, 08 Feb 2012 22:51:14 +0000 hourly 1 http://wordpress.org/?v=3.0.3 By: David Aldridge http://www.dbms2.com/2006/02/05/tom-kyte-on-constraints/#comment-9273 David Aldridge Tue, 03 Oct 2006 04:11:39 +0000 http://www.dbms2.com/?p=56#comment-9273 I'm a little surprised that Tom didn't mention the declaration of dimensions as well, as they are a logical expansion of constraints that allow further flexibility for query rewrite. Theyu allow the declaration of multiple hierarchies within a data set and the specification of levels within the hierarchies and the data elements that are attributes of the different levels. They are purely declarative and are not enforceable, although there are procedures for validating that the data does not contravene the declared rules. Documentation here: http://download-west.oracle.com/docs/cd/B19306_01/server.102/b14223/qradv.htm#BABDGGGB I’m a little surprised that Tom didn’t mention the declaration of dimensions as well, as they are a logical expansion of constraints that allow further flexibility for query rewrite. Theyu allow the declaration of multiple hierarchies within a data set and the specification of levels within the hierarchies and the data elements that are attributes of the different levels.

They are purely declarative and are not enforceable, although there are procedures for validating that the data does not contravene the declared rules.

Documentation here: http://download-west.oracle.com/docs/cd/B19306_01/server.102/b14223/qradv.htm#BABDGGGB

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