TABLE OF CONTENTS Section 2.4 included an overview of the information systems life cycle. So far, we ve focused on the stages of this cycle that deal with the conceptual and logical design of the data. We ve seen how to perform conceptual data modeling using ORM, ER, or UML, and applied the Rmap algorithm to map a conceptual schema to a relational database schema. We ve discussed how to query a relational schema using SQL, and applied conceptual schema transformations and lower-level optimizations to improve the efficiency of the implemented design.
This chapter discusses other aspects and recent trends related to modeling and querying information systems. We ll be covering a lot of ground, so the treatment of each topic is necessarily brief. You can use the references in the chapter notes to dive deeper into the areas examined.
Section 13.2 provides a brief introduction to data warehousing and online analytical processing. Section 13.3 discusses some very high level languages for querying information systems. Section 13.4 outlines some ways of performing schema abstraction, enabling the modeler to focus on various aspects of a schema by hiding other details. Section 13.5 presents an overview of process modeling and external schema design. Often, the design of external interfaces (e.g., screen forms) can be viewed in terms of operations on the major object types abstracted from the conceptual data model.
Section 13.6 examines the claim that relational databases should be replaced by object-oriented databases or other kinds of databases. It also mentions some other issues and...
