Chapter 2. Database Objects | DB2(R) Universal Database for OS/390 V7.1 Application Certification Guide (IBM DB2 Certification Guide Series)

021 - Chapter 2. Database Objects <ul><li> <p clas><script> function OpenWin(url, w, h) { if(!w) w = 400; if(!h) h = 300; window. open (url, "_new", "width=" + w + ",height=" + h + ",menubar=no,toobar=no,scrollbars=yes", true); } function Print() { window.focus(); if(window.print) { window.print(); window.setTimeout('window.close();',5000); } } </script><span></span></p> <table width="100%" cellpadding="0" cellspacing="0" border="0"><tr valign="top"></tr></table> <table width="100%" height="20" border="0" cellpadding="0" cellspacing="1"><tr></tr></table> <table width="100%" border="0" cellspacing="0" cellpadding="0"><tr valign="top"><td align="center"><table width="95%"><tr><td align="left"> <table width="100%" border="0" cellspacing="0" cellpadding="2"> <tr><td valign="top" height="5"><img src="/books/2/607/1/html/2/images/pixel.gif" width="1" height="5" alt="" border="0"></td></tr> <tr> <td><b><font size="1" color ="#0000FF">Team-Fly<img border="0" src="/books/2/607/1/html/2/Fly-Logo.gif" width="81" height="25"></font></b></td> <td valign="top" align="right"> </td> </tr> </table> <hr size="1"> <table width="100%" border="0" cellspacing="0" cellpadding="5"> <tr> <td valign="top" width="76" rowspan="4"><img src="/books/2/607/1/html/2/images/0131007718/0131007718_xs.jpg" width="76" height="95" border="0"></td> <td valign="top">DB2 Universal Database for OS/390 v7.1 Application Certification Guide<br>By Susan Lawson<br> </td> </tr> <tr><td>Table of Contents</td></tr> <tr><td></td></tr> <tr><td valign="bottom">Part 1. Introduction to DB2 UDB for OS/390 and z/OS</td></tr> </table> <hr size ="1"> <br><table width="100%" border="0" cellspacing="0" cellpadding ="0"><tr><td valign="top"> <h2>Chapter 2. Database Objects</h2> <ul> <li><p>Creating Database Objects</p></li> <li><p>Data Types</p></li> <li><p>Tables and Tablespaces</p></li> <li><p>Aliases and Synonyms</p></li> <li><p>Constraints</p></li> <li><p>Views</p></li> <li><p>Indexes</p></li> </ul> <p>DB2 is a relational database that consists of one or more tables that are made up of rows and columns . The tables are created and accessed using the industry standard SQL (Structured Query Language). Data in these tables is accessed via content, not location. This chapter looks at the structures in a DB2 subsystem and those that make up a DB2 database.</p> <p>Many of these objects can be directly referenced from a SQL statement; therefore, it is important to understand their purpose. SQL is divided into three major categories:</p> <ul> <li><p>DDL (Data Definition Language) is used to create, modify, or drop database objects.</p></li> <li><p>DML (Data Manipulation Language) is used to select, insert, update, or delete database data (records).</p></li> <li><p>DCL (Data Control Language) is used to provide data object access control.</p></li> </ul> <p>As SQL has evolved, many new statements have been added to provide a more complete set of data access methods . Later in this chapter, the use of DDL to create database objects is discussed.</p> </td></tr></table> <hr size="1"> <table width="100%" border="0" cellspacing="0" cellpadding="2"> <tr><td valign="top" height="5"><img src="/books/2/607/1/html/2/images/pixel.gif" width="1" height="5" alt="" border="0"></td></tr> <tr> <td><b><font size="1" color="#0000FF">Team-Fly<img border="0" src="/books/2/607/1/html/2/Fly-Logo.gif" width="81" height="25"></font></b></td> <td valign="top" align="right"> </td> </tr> </table> <table width="100%" border="0" cellspacing="0" cellpadding="0"><tr><td valign="top" align="right">Top</td></tr></table> </td></tr></table></td></tr></table> </li></ul>