Understanding DB2: Learning Visually with Examples (2nd Edition)

2.8. Summary

This chapter provided an overview of the DB2 core concepts using a "big picture" approach. It introduced SQL statements and their classification in Data Definition Language (DDL), Data Manipulation Language (DML), and Data Control Language (DCL).

DB2 commands are classified into two groupssystem commands and CLP commandsand several examples were provided, like the command to start an instance, db2start.

You need an interface to issue SQL statements and commands to the DB2 engine. This interface was provided by using the DB2 tools available with the product. Two text-based interfaces were mentioned, the Command Line Processor (CLP) and the Command Window. The Control Center was noted as being the most important administration graphical tool.

The chapter introduced the concepts of instances, databases, table spaces, buffer pools, logs, tables, indexes, and other database objects in a single partition system. There are different levels of configuration for the DB2 environment: the environment variables, the DB2 registry variables, and the configuration parameters at the instance (dbm cfg) and database (db cfg) levels. DB2 has federation support for queries using tables from other databases in the DB2 family. The chapter also covered database partition, catalog partition, coordinator node, and partitioning map on a multipartition system.

Two case studies reviewed the single-partition and multipartition environments respectively, which should help you understand the topics discussed in the chapter.