DB2 - Tutorial




DB2 Introduction

DB2 is well known as Data base 2 which is introduced by IBM. It is known as Relational database (Relational is nothing but the data stored will have a relation in between). The relational data stored in format of TABLE which contains Tuples (ROWS) and the row consists of Attributes (COLUMNS). DB2 is almost similar to the SQL (Structured Query Language) but with some additional features and mainly used to process the large amount of data from the Mainframe application.

The tutorial is intended for the readers with no previous programming or computer science experience as well as for those with some computing background. In the tutorial, all the topics are covered with in depth description and can understandable by anyone who had minimum/no computation background.

This tutorial shows you how to use Db2 for z/OS® in the z/OS terminal interface to complete some basic database administration tasks. You might use many different tools and environments to work with Db2 for z/OS in your job. Many of these methods use batch jobs or database applications that are programmed in advance and that run in the background, with little or no direct human interaction. However, you can also work with Db2 for z/OS through interactive methods such as commands and menu-style user interfaces. For example, you can use the SPUFI (SQL processor using file input) facility within the DB2I (Db2 Interactive) primary option menu of ISPF to work with SQL statements interactively. You can edit SQL statements in SPUFI, issue the statements, and see the results immediately.

What is DB2?

A relational database is based on the principle of relation and relation can be anything. For example, there can be a relation between rows and columns or there can be a relation between tables. Relational database follows the principle of RDBMS. RDBMS is a relational database management system.

DB2 is a subsystem of the MVS operating system. It is a Database Management System (DBMS) for that operating system.

Since the 1970s, when IBM Research invented the Relational Model and the Structured Query Language (SQL), IBM has developed a complete family of RDBMS software. Development started on mainframe platforms such as Virtual Machine (VM), Virtual Storage Extended (VSE), and Multiple Virtual Storage (MVS). In 1983, DB2 for MVS Version 1 was born. "DB2" was used to indicate a shift from hierarchical databases&8212;like the Information Management System (IMS) popular at the time&8212;to the new relational databases. DB2 development continued on mainframe platforms as well as on distributed platforms.

In 1996, IBM announced DB2 UDB Version 5 for distributed platforms. With this version, DB2 was able to store all kinds of electronic data, including traditional relational data, as well as audio, video, and text documents. It was the first version optimized for the Web, and it supported a range of distributed platforms&8212;for example, OS/2, Windows, AIX, HP-UX, and Solaris&8212;from multiple vendors. Moreover, this universal database was able to run on a variety of hardware, from uniprocessor systems and symmetric multiprocessor (SMP) systems to massively parallel processing (MPP) systems and clusters of SMP systems. IBM included the term "Universal" in the name to represent the new capabilities of this version. All versions of DB2 on distributed platforms and on MVS, AS/400, VM, and VSE have adopted the name DB2 UDB.

Today, DB2 represents a portfolio of information management products. Table 1.1 shows the DB2 Information Management portfolio and the product offerings under each classification. To specifically refer to database servers, "UDB" needs to be added to the name, as in DB2 UDB . In most books and documents, including this one, the terms "DB2" and "DB2 UDB" are used interchangeably. Unless otherwise noted, when we use any one of these terms in this book, we are referring to DB2 running on Linux, UNIX, or Windows.