Database Strategies Using Informix XPS and DB2 Universal Database
ISBN : 0738493740
Cover Design - Database Strategies Using Informix XPS and DB2 Universal Database
For your free electronic copy of this book please verify the numbers below.
(We need to do this to make sure you're a person and not a malicious script)
Sample Chapter From Database Strategies Using Informix XPS and DB2 Universal Database
Copyright © Chuck Ballard, Weiren Ding, Carlton Doe, Glen Mules, Rajamani Muralidharan, Santosh Sajip, Nora Sokolof, Andreas Weininger
XPS and DB2 UDB Architectures
This chapter describes the architectures of the IBM Informix Extended Parallel Server (XPS) and DB2 Universal Database (DB2 UDB) relational database management system (RDBMS) products.
Understanding the product architectures is critical if you are considering a transition from XPS to DB2. This chapter compares and contrasts these architectures at a medium- to low-level of detail, which includes, but is not limited to, memory sizing, process considerations, and disk (data storage) allocation. For DB2 UDB, it concentrates specifically on DB2 UDB Enterprise Server Edition (ESE) with the Data Partitioning Feature (DPF), because this version of DB2 includes — as does XPS — support for cluster and massively parallel processing systems (MPP). When describing DB2, this chapter is not restricted to the database server itself but includes products of the DB2 Data Warehouse Edition, because some of the functionality that is available with XPS and its bundled utilities is available for DB2 from products in the DB2 Data Warehouse Edition. For example, some of the functionality of Informix I-Spy is provided by DB2 Query Patroller, which is part of the DB2 Data Warehouse Edition.
Although mentioned briefly in this chapter, this chapter does not cover the full configuration of either product. You can find additional details about configuration in Chapter 3, “Configuration” on page 63. In addition, this chapter touches upon performance tuning considerations. However, it does not discuss the topic at any substantial depth. You should consider performance tuning after the transition,
but such tuning is a function of your particular environment.
Both XPS and DB2 share many similar concepts, components, and architectural structures. However, these products also have significant differences. You should take these differences into consideration during the transition process.
The terminologies of XPS and DB2 vary slightly in some areas and more significantly in other areas. This chapter describes the terminology that is used as well as the component definitions to promote a common understanding.
Within this chapter, each topic uses the following format:
Introduction to topic area, with minor comparisons for clarity
Topic description relative to the XPS architecture
Topic description relative to the DB2 architecture
Topic description relative to the XPS architecture
Topic description relative to the DB2 architecture
A dilemma that is encountered typically in a discussion of this type is finding common terms for what is described. For example, this chapter describes the architecture and components of database management systems. Specifically, it refers to actual implementations of the XPS and DB2 database management systems. Customers and developers often refer to such implementations in a variety of terms (such as servers, engines, online systems, database servers, instances, or even simply as databases). For this redbook, we use the term instance to describe the implementation of the database management system.