16.1. Introduction

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 database manipulation using SQL and XML, modeled business processes and states, and applied conceptual schema transformations and lower level optimizations to improve the efficiency of relational designs.

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 16.2 provides a brief introduction to data warehousing and online analytical processing. Section 16.3 discusses some very high level languages for querying information systems. Section 16.4 outlines some ways of performing schema abstraction, enabling the modeler to focus on various aspects of a schema by hiding other details.

Section 6.5 discusses further design aspects, such as coordinating data and process models, and user interface design. Section 16.6 outlines some recent work on ontologies and the semantic web. Section 16.7 examines recent extensions to or replacements of relational databases, such as object-oriented capabilities and XML. Section 16.8 provides an introduction to metamodeling, in which schemas themselves are treated as instances of a higher level metaschema. Section 16.9 furnishes a summary to complete this final chapter.