81 lines
4.6 KiB
HTML
81 lines
4.6 KiB
HTML
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<?xml version="1.0" encoding="UTF-8"?>
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<!DOCTYPE html
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PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
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<html lang="en-us" xml:lang="en-us">
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<head>
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<meta name="DC.Type" content="concept" />
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<meta name="DC.Title" content="Save access paths" />
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<meta name="DC.Relation" scheme="URI" content="rzaiurzaiu130.htm" />
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<meta name="DC.Relation" scheme="URI" content="rzaiurzaiu133.htm" />
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<meta name="copyright" content="(C) Copyright IBM Corporation 2004, 2006" />
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<!-- All rights reserved. Licensed Materials Property of IBM -->
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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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<link rel="stylesheet" type="text/css" href="./ibmdita.css" />
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<link rel="stylesheet" type="text/css" href="./ic.css" />
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<title>Save access paths</title>
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</head>
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<body id="rzaiu132"><a name="rzaiu132"><!-- --></a>
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<!-- Java sync-link --><script language="Javascript" src="../rzahg/synch.js" type="text/javascript"></script>
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<h1 class="topictitle1">Save access paths</h1>
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<div><p>When you restore a database file, but you did not save the access path
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to the database, the server rebuilds the access path. You can significantly
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reduce the amount of time it takes you to recover if you save the access paths.
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However, the process that saves access paths increases the time for the save
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operation and the amount of media that you use.</p>
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<p>To save access paths that are owned by logical files, specify ACCPTH(*YES)
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on the SAVCHGOBJ, SAVLIB, and SAVOBJ commands when you save the physical files.
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The server saves access paths when you save the physical file because the
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physical file contains the data that is associated with the access path. When
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you save the logical file, you are saving only the description of the logical
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file.</p>
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<p>When a save command (SAVLIB, SAVOBJ, SAVCHGOBJ, SAVRSTLIB, SAVRSTOBJ, or
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SAVRSTCHG) is performed, the save access paths parameter value is determined
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by the QSAVACCPTH system value when ACCPTH(*SYSVAL) is specified. When ACCPTH(*YES)
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or ACCPTH(*NO) is specified, this system value is ignored. If access paths
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are to be saved, the process that saves access paths increases the time for
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the save operation and the amount of media that you use. However, by having
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the access paths saved, you significantly reduce the amount of time it takes
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to recover a system because the access paths do not need to be rebuilt.</p>
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<p>The server saves access paths that logical files own, and that are not
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used for referential constraints if all of the following are true: </p>
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<ul><li>You specify ACCPTH(*YES) on the save command for the physical files.</li>
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<li>All based-on physical files under the logical file are in the same library
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and are being saved at the same time on the same save command.</li>
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<li>The logical file is MAINT(*IMMED) or MAINT(*DLY).</li>
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</ul>
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<p>In all cases, the server saves an access path only if it is valid and not
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damaged at the time of the save operation.</p>
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<p>When you save a physical file that is not a source file, the server saves
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the following types of access paths with it, even if you do or do not specify
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ACCPTH(*YES): </p>
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<ul><li>Keyed access paths that are owned by the physical file</li>
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<li>Primary key constraints</li>
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<li>Unique constraints</li>
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<li>Referential constraints</li>
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</ul>
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<p>If the based-on physical files and the logical files are in different libraries,
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the server saves the access paths. However, the server may not restore these
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access paths. Look for information about restoring access paths in the <a href="../books/sc415304.pdf" target="_blank">Backup and Recovery book</a><img src="wbpdf.gif" alt="Link to PDF" />.</p>
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</div>
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<div>
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<ul class="ullinks">
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<li class="ulchildlink"><strong><a href="rzaiurzaiu133.htm">EXAMPLE - Saving files in a network</a></strong><br />
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</li>
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</ul>
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<div class="familylinks">
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<div class="parentlink"><strong>Parent topic:</strong> <a href="rzaiurzaiu130.htm">Save database files</a></div>
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</div>
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</div>
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</body>
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</html>
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