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The following technical report from University of Alberta, Department
of Computing Science is available and may be of interest to followers
of this newsgroup.


			   TIGUKAT:
	  An Object Model for Query and View Support
    			      in
		   Object Database Systems

			      by
							   
			Randal J. Peters
			 M. Tamer Ozsu
			 Duane Szafron
								   
								   
		  Technical Report TR 92-14
			 October 1992

ABSTRACT

Object-oriented computing is influencing many areas of computer
science including software engineering, user interfaces, operating
systems, programming languages and database systems. The appeal of
object-orientation is attributed to its higher levels of abstraction
for modeling real world concepts, its support for incremental
development and its potential for interoperability.  Despite many
advances, object-oriented computing is still in its infancy and a
universally acceptable definition of an object-oriented data model is
virtually nonexistent, although some standardization efforts are
underway.  This report presents the TIGUKAT(*) object model definition
that is the result of an investigation of object-oriented modeling
features which are common among earlier proposals, along with some
distinctive qualities that extend the power and expressibility of this
model beyond others. The literature recognizes two perspectives of an
object model: the structural view and the behavioral view.  Most
object-oriented formalisms have concentrated on one or the other of
these two perceptions. The TIGUKAT object model (i) favors formal
specifications for both the behavioral and structural components, and
(ii) shows an integration of the two components into a complete model
definition.  Furthermore, the model emphasizes (iii) a clean
separation and precise definition of object modeling features which
are usually bundled and only intuitively defined in other models, and
(iv) a uniform approach to object modeling which encompasses all
information, including meta-data, as objects within the primitive
definitions.

The establishment of a formal object model provides a theoretical
foundation from which investigations of other object database features
will be pursued.  The first of these involves the definition of an
object query model with complete calculus and algebra specifications,
including an equivalence transformation proof between the two.  Based
on the query model, object views and view management with update
semantics will be examined.  The intention is to incorporate very
powerful and dynamic object definition and manipulation language
features into the model. In parallel with this, a dynamic schema
evolution policy will be developed for integrating new types into the
model. We are currently in the process of implementing the model
presented in this report to establish a workable software base with
the long range goal of developing a full-featured object database
management system.

-------------------------------------------
*TIGUKAT (tee-goo-kat) is a term in the language of the Canadian Inuit
people meaning "objects." The Canadian Inuits, commonly known as
Eskimos, are native to Canada with an ancestry originating in the
Arctic regions of the country.


To obtain a copy of this report, either 

(1) via anonymous ftp from menaik.cs.ualberta.ca (129.128.4.241).
Instead of password, you will be asked for an "ident" which should be
the id of the machine you are ftp'ing from. Enter directory 

	~ftp/pub/TechReports

There are two compressed files: TR92-14.dvi.Z and TR92-14.ps.Z. The
dvi file is larger but may be easier to print at other sites. You have
to uncompress these files after you have ftp'ed them.

(2) send email to britta@cs.ualberta.ca, or 
(3) write to
		Britta Nielsen
		Department of Computing Science
		University of Alberta
		Edmonton, Alberta
		Canada T6G 2H1


--
____________________________________________________________________________
M. Tamer Ozsu			   Internet: ozsu@cs.ualberta.ca	
Department of Computing Science    Tel: (403) 492-2860; Fax: (403) 492-1071
University of Alberta		   Edmonton, Alberta, Canada T6G 2H1
===========================================================================
Co-moderator:  Richard Golding, Computer & Information Sciences, UC Santa Cruz
	    compdoc-techreports-request@ftp.cse.ucsc.edu