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Chapter 9 Object-Relational DBMSs
9.1 Compare and contrast the two manifestos: Object-Oriented Database System Manifesto based on
the object-oriented paradigm (Atkinson et al., 1989a) and the Third Generation Database System
Manifesto published by the Committee for Advanced DBMS Function (CADF).
9.2 Discuss how the new version of the SQL standard addresses object-oriented data management.
Give examples to illustrate your answers.
9.3 The on-going debate between proponents of the relational data model and proponents of the
object-oriented data model (if one truly exists), resembles that between the proponents of
network/hierarchic systems and relational systems a couple of decades ago. However, another
system is evolving that may have a significant impact on what the database management system of
the future may be and that is the Object-Relational Database Management System (ORDBMS).
9.4 Discuss how the proposed SQL:2011 standard will handle object identity and give an example of
its intended use.
Object identity in SQL:2011 achieved through a referenceable base table. For example:
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9.5 Consider the following schema:
where:
Pet contains details of pets and the pet number (petNo) is the key. The surgery where the
Now consider the following SQL:2003 query:
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Discuss how you would want a query optimiser within an ORDBMS to handle this type of query.
Use a relational algebra tree to illustrate your answer.
9.6 Given the following example of an object type in Oracle:
CREATE TYPE carType AS OBJECT (
regNo VARCHAR2 (8),
make VARCHAR2 (20),
model VARCHAR2 (20));
CREATE TABLE vehicles OF carType;
State the two ways:
(a)
(b)
(c) to retrieve recor
9.7 In the Object Relational Model (ORM) an object-type has a name, attributes, and methods.
What is a method? And what is the principal use of methods?
What kinds of methods are supported by Oracle ORM.