51 lines
3.1 KiB
HTML
51 lines
3.1 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 http-equiv="Content-Type" content="text/html; charset=utf-8" />
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<meta http-equiv="PICS-Label" content='(PICS-1.1 "http://www.icra.org/ratingsv02.html" l gen true r (cz 1 lz 1 nz 1 oz 1 vz 1) "http://www.rsac.org/ratingsv01.html" l gen true r (n 0 s 0 v 0 l 0) "http://www.classify.org/safesurf/" l gen true r (SS~~000 1))' />
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<meta name="DC.Type" content="concept" />
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<meta name="DC.Title" content="Data integrity considerations" />
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<meta name="abstract" content="Consider data integrity when using join logical files." />
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<meta name="description" content="Consider data integrity when using join logical files." />
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<meta name="DC.subject" content="data, integrity considerations, ensuring data integrity" />
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<meta name="keywords" content="data, integrity considerations, ensuring data integrity" />
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<meta name="DC.Relation" scheme="URI" content="rbafojoincons.htm" />
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<meta name="copyright" content="(C) Copyright IBM Corporation 1998, 2006" />
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<meta name="DC.Rights.Owner" content="(C) Copyright IBM Corporation 1998, 2006" />
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<meta name="DC.Format" content="XHTML" />
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<meta name="DC.Identifier" content="rbafodicon" />
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<meta name="DC.Language" content="en-us" />
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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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<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>Data integrity considerations</title>
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</head>
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<body id="rbafodicon"><a name="rbafodicon"><!-- --></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">Data integrity considerations</h1>
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<div><p>Consider data integrity when using join logical files. </p>
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<div class="p">Unless you have a lock on the physical files used by the join logical file,
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the following situations can occur: <ul><li>Your program reads a record for which there are two or more records in
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a secondary file. The system supplies one record to your program.</li>
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<li>Another program updates the record in the primary file that your program
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has just read, changing the join field.</li>
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<li>Your program issues another read request. The system supplies the next
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record based on the current (new) value of the join field in the primary file.</li>
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</ul>
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</div>
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<p>These same considerations apply to secondary files as well.</p>
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</div>
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<div>
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<div class="familylinks">
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<div class="parentlink"><strong>Parent topic:</strong> <a href="rbafojoincons.htm" title="These topics include the performance and integrity considerations for join logical files. They also provide a summary of rules for join logical files.">Join logical file considerations</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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