mirror of
https://github.com/yasuhirokimura/db18
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Yasuhiro KIMURA
149 lines
6.1 KiB
HTML
149 lines
6.1 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>Restrictions on XA Transactions</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 Programmer's Reference Guide" />
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<link rel="up" href="xa.html" title="Chapter 14. Distributed Transactions" />
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<link rel="prev" href="xa_xa_config.html" title="Configuring Berkeley DB with the Tuxedo System" />
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<link rel="next" href="xa_faq.html" title="XA: Frequently Asked Questions" />
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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 18.1.40</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">Restrictions on XA Transactions</th>
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</tr>
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<tr>
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<td width="20%" align="left"><a accesskey="p" href="xa_xa_config.html">Prev</a> </td>
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<th width="60%" align="center">Chapter 14. Distributed Transactions </th>
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<td width="20%" align="right"> <a accesskey="n" href="xa_faq.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="xa_xa_restrict"></a>Restrictions on XA Transactions</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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When you are using Berkeley DB for XA transactions, there
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are a few restrictions you should be aware of:
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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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Configure environment using the <a href="../api_reference/C/configuration_reference.html" class="olink">DB_CONFIG</a> file
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</p>
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<p>
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For most options, you must configure your
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environment via the <a href="../api_reference/C/configuration_reference.html" class="olink">DB_CONFIG</a> file because an XA
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application or server cannot control the environment
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creation.
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</p>
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</li>
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<li>
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<p>
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Snapshot isolation must be configured for the
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entire environment.
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</p>
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<p>
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Transactions managed by the Berkeley DB X/open
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compliant XA resource manager can be configured for
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transaction snapshots using either database open flags
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or the <a href="../api_reference/C/configuration_reference.html" class="olink">DB_CONFIG</a> file file. To configure using database
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open flags, open the XA managed database with the flag
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<a href="../api_reference/C/dbopen.html#dbopen_DB_MULTIVERSION" class="olink">DB_MULTIVERSION</a>. When using DB_CONFIG, include both
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of the following lines:
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</p>
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<pre class="programlisting">set_flags DB_MULTIVERSION
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set_flags DB_TXN_SNAPSHOT</pre>
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<p>
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Note that both methods will results in all
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transactions using transaction snapshots, there is no
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way to enable transaction snapshots in just a subset
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of XA managed transactions.
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</p>
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</li>
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<li>
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<p>
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No in-memory logging
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</p>
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<p>
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Upon return from xa_open, Berkeley DB checks to
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ensure there is no in-memory logging. If in-memory
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logging is detected, a FAILURE message is returned to
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the application.
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</p>
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</li>
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<li>
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<p>
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No application-level child transactions
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</p>
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<p>
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Berkeley DB verifies in the xa_start and xa_end
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calls that no XA transaction has a parent. If
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application-level child transactions are detected, a
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FAILURE message is returned to the application.
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</p>
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</li>
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<li>
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<p>
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All database-level operations, such as create,
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rename, and remove, must be performed in local BDB
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transactions, not distributed XA transactions
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</p>
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<p>
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Berkeley DB checks that there is no XA transaction
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currently active during these operations, and if
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detected, a FAILURE message is returned to the
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application.
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</p>
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</li>
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<li>
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<p>
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Close cursors before a service invocation returns
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</p>
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<p>
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Berkeley DB checks in the <code class="literal">xa_end</code>
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call that the <code class="literal">DB_TXN</code> has no active
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cursors open and and if detected, a FAILURE message is
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returned to the application.
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</p>
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</li>
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</ul>
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</div>
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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="xa_xa_config.html">Prev</a> </td>
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<td width="20%" align="center">
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<a accesskey="u" href="xa.html">Up</a>
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</td>
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<td width="40%" align="right"> <a accesskey="n" href="xa_faq.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">Configuring Berkeley DB with the Tuxedo System </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"> XA: Frequently Asked Questions</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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