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96 lines
4.1 KiB
HTML
96 lines
4.1 KiB
HTML
<?xml version="1.0" encoding="UTF-8" standalone="no"?>
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<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
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<html xmlns="http://www.w3.org/1999/xhtml">
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<head>
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<meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
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<title>Registering DPL Secondary Keys</title>
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<link rel="stylesheet" href="gettingStarted.css" type="text/css" />
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<meta name="generator" content="DocBook XSL Stylesheets V1.73.2" />
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<link rel="start" href="index.html" title="Berkeley DB Installation and Build Guide" />
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<link rel="up" href="upgrade_4_8_toc.html" title="Chapter 13. Upgrading Berkeley DB 4.7 applications to Berkeley DB 4.8" />
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<link rel="prev" href="upgrade_4_8_toc.html" title="Chapter 13. Upgrading Berkeley DB 4.7 applications to Berkeley DB 4.8" />
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<link rel="next" href="upgrade_4_8_mpool.html" title="Minor Change in Behavior of DB_MPOOLFILE->get" />
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</head>
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<body>
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<div xmlns="" class="navheader">
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<div class="libver">
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<p>Library Version 11.2.5.3</p>
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</div>
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<table width="100%" summary="Navigation header">
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<tr>
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<th colspan="3" align="center">Registering DPL Secondary Keys</th>
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</tr>
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<tr>
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<td width="20%" align="left"><a accesskey="p" href="upgrade_4_8_toc.html">Prev</a> </td>
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<th width="60%" align="center">Chapter 13. Upgrading Berkeley DB 4.7 applications to Berkeley DB 4.8</th>
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<td width="20%" align="right"> <a accesskey="n" href="upgrade_4_8_mpool.html">Next</a></td>
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</tr>
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</table>
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<hr />
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</div>
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<div class="sect1" lang="en" xml:lang="en">
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<div class="titlepage">
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<div>
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<div>
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<h2 class="title" style="clear: both"><a id="upgrade_4_8_dpl"></a>Registering DPL Secondary Keys</h2>
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</div>
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</div>
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</div>
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<p>
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Entity subclasses that define secondary keys must now be registered
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prior to storing an instance of the class. This can be done in two
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ways:
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</p>
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<div class="itemizedlist">
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<ul type="disc">
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<li>
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<p>
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The <code class="methodname">EntityModel.registerClass()</code> method
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may be called to register the subclass before opening the
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entity store.
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</p>
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</li>
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<li>
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<p>
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The <code class="methodname">EntityStore.getSubclassIndex()</code>
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method may be called to implicitly register the subclass after
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opening the entity store.
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</p>
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</li>
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</ul>
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</div>
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<p>
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Failure to register the entity subclass will result in an
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<code class="classname">IllegalArgumentException</code> the first time an
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attempt is made to store an instance of the subclass. An exception will
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not occur if instances of the subclass have previously been stored,
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which allows existing applications to run unmodified in most cases.
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</p>
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<p>
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This behavioral change was made to increase reliability. In several
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cases, registering an entity subclass has been necessary as a
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workaround. The requirement to register the subclass will ensure that
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such errors do not occur in deployed applications.
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</p>
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</div>
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<div class="navfooter">
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<hr />
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<table width="100%" summary="Navigation footer">
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<tr>
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<td width="40%" align="left"><a accesskey="p" href="upgrade_4_8_toc.html">Prev</a> </td>
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<td width="20%" align="center">
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<a accesskey="u" href="upgrade_4_8_toc.html">Up</a>
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</td>
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<td width="40%" align="right"> <a accesskey="n" href="upgrade_4_8_mpool.html">Next</a></td>
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</tr>
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<tr>
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<td width="40%" align="left" valign="top">Chapter 13. Upgrading Berkeley DB 4.7 applications to Berkeley DB 4.8 </td>
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<td width="20%" align="center">
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<a accesskey="h" href="index.html">Home</a>
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</td>
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<td width="40%" align="right" valign="top"> Minor Change in Behavior of DB_MPOOLFILE->get</td>
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</tr>
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</table>
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</div>
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</body>
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</html>
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