93 lines
3.1 KiB
HTML
93 lines
3.1 KiB
HTML
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<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
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<html>
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<head>
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<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
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<meta name="Copyright" content="Copyright (c) 2006 by IBM Corporation">
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<title>Using User Index APIs</title>
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<!-- All rights reserved. Licensed Materials Property of IBM -->
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<!-- US Government Users Restricted Rights -->
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<!-- Use, duplication or disclosure restricted by -->
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<!-- GSA ADP Schedule Contract with IBM Corp. -->
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<!-- Change History: -->
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<!-- YYMMDD USERID Change description -->
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<!-- End Header Records -->
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<link rel="stylesheet" type="text/css" href="../rzahg/ic.css">
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</head>
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<body>
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<!-- Java sync-link -->
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<script type="text/javascript" language="Javascript" src="../rzahg/synch.js">
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</script>
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<a name="Top_Of_Page"></a>
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<h2>Using User Index APIs</h2>
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<p>A <strong>user index</strong> is an object that allows search functions for
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data in the index and automatically sorts data based on the value of the data.
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User indexes are permanent objects in the user domain or in the system domain.
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They have an object type of *USRIDX and a maximum size of
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1 terabyte (1 099 511 627 776 bytes).
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They help streamline table searching,
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cross-referencing, and ordering of data. In general, if your table is longer
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than 1000 entries, an index performs faster than a user-sorted table.</p>
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<p>You can use user indexes to:</p>
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<ul>
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<li>Provide search functions</li>
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<li>Do faster insert operations than in a database file</li>
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<li>Do faster retrieve operations than in a database file</li>
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<li>Create an index by name, such as a telephone directory</li>
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<li>Use order entry programs</li>
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<li>Look up abbreviations in an index</li>
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<li>Sort data automatically based on the hexadecimal value of a key</li>
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</ul>
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<p>User index
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entries cannot contain a pointer. You can save and restore all the data
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in an index. You can also save and restore user indexes to another system.
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For more information about user index considerations, refer to the
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<a href="../apiref/conIndexCons.htm" target="_blank">User index considerations</a>
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in API concepts.
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</p>
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<p> In addition to the user index APIs, you can work with user indexes through
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the following:</p>
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<ul>
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<li>ILE C programming language</li>
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<li>Machine interface (MI) instructions</li>
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<li>Delete User Index (DLTUSRIDX) command</li>
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</ul>
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<p>For details about MI instructions, refer to the
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<a href="../rzatk/mitoc.htm">iSeries
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Machine Interface Instructions</a>, which provides detailed descriptions of the
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iSeries<SUP>(TM)</SUP> machine interface instruction fields and the formats of those fields.
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For details about the DLTUSRIDX command,
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see the <a href="../rbam6/rbam6clmain.htm">Control Language (CL)</a> topic.</p>
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<hr>
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<center>
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<table cellpadding="2" cellspacing="2">
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<tr align="center">
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<td valign="middle" align="center">
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<a href="#Top_Of_Page">Top</a> |
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<a href="obj1.htm">Object APIs</a> |
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<a href="aplist.htm">APIs by category</a></td>
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</tr>
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</table>
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</center>
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</body>
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</html>
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