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218 lines
9.5 KiB
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<?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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<head>
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<meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
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<title>db_checkpoint</title>
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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 C API Reference" />
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<link rel="up" href="utilities.html" title="Appendix A. Berkeley DB Command Line Utilities" />
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<link rel="prev" href="db_archive.html" title="db_archive" />
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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 11.2.5.2</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">db_checkpoint</th>
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</tr>
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<tr>
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<td width="20%" align="left"><a accesskey="p" href="db_archive.html">Prev</a> </td>
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<th width="60%" align="center">Appendix A.
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Berkeley DB Command Line Utilities
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</th>
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<td width="20%" align="right"> <a accesskey="n" href="db_deadlock.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="db_checkpoint"></a>db_checkpoint</h2>
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</div>
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</div>
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</div>
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<pre class="programlisting">db_checkpoint [-1Vv] [-h home]
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[-k kbytes] [-L file] [-P password] [-p min] </pre>
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<p>
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The <span class="command"><strong>db_checkpoint</strong></span> utility is a daemon process that monitors the
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database log, and periodically calls
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<a class="xref" href="txncheckpoint.html" title="DB_ENV->txn_checkpoint()">DB_ENV->txn_checkpoint()</a>
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to checkpoint it.
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</p>
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<p>
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The options are as follows:
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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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<span class="bold"><strong>-1</strong></span>
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</p>
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<p>
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Force a single checkpoint of the log (regardless of whether or not
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there has been activity since the last checkpoint), and then exit.
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</p>
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<p>
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When the <span class="bold"><strong>-1</strong></span> flag is specified, the
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<span class="command"><strong>db_checkpoint</strong></span> utility will checkpoint the log even if unable to find
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an existing database environment. This functionality is useful when
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upgrading database environments from one version of Berkeley DB to
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another.
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</p>
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</li>
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<li>
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<p>
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<span class="bold"><strong>-h</strong></span>
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</p>
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<p>
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Specify a home directory for the database environment; by default, the
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current working directory is used.
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</p>
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</li>
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<li>
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<p>
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<span class="bold"><strong>-k</strong></span>
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</p>
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<p>
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Checkpoint the database at least as often as every <span class="bold"><strong>kbytes</strong></span> of log file are written.
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</p>
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</li>
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<li>
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<p>
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<span class="bold"><strong>-L</strong></span>
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</p>
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<p>
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Log the execution of the <span class="command"><strong>db_checkpoint</strong></span> utility to the specified file
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in the following format, where <span class="emphasis"><em>###</em></span> is the process
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ID, and the date is the time the utility was started.
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</p>
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<pre class="programlisting"> db_checkpoint: ### Wed Jun 15 01:23:45 EDT 1995 </pre>
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<p>
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This file will be removed if the <span class="command"><strong>db_checkpoint</strong></span>
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utility exits gracefully.
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</p>
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</li>
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<li>
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<p>
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<span class="bold"><strong>-P</strong></span>
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</p>
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<p>
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Specify an environment password. Although Berkeley DB utilities overwrite password
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strings as soon as possible, be aware there may be a window of vulnerability on
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systems where unprivileged users can see command-line arguments or where utilities
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are not able to overwrite the memory containing the command-line arguments.
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</p>
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</li>
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<li>
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<p>
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<span class="bold"><strong>-p</strong></span>
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</p>
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<p>
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Checkpoint the database at least every <span class="bold"><strong>min</strong></span> minutes
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if there has been any activity since the last checkpoint.
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</p>
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</li>
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<li>
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<p>
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<span class="bold"><strong>-V</strong></span>
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</p>
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<p>
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Write the library version number to the standard output, and exit.
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</p>
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</li>
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<li>
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<p>
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<span class="bold"><strong>-v</strong></span>
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</p>
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<p>
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Write the time of each checkpoint attempt to the standard output.
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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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At least one of the <span class="bold"><strong>-1</strong></span>, <span class="bold"><strong>-k</strong></span>, and <span class="bold"><strong>-p</strong></span>
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options must be specified.
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</p>
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<p>
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The <span class="command"><strong>db_checkpoint</strong></span> utility uses a Berkeley DB
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environment (as described for the <span class="bold"><strong>-h</strong></span>
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option, the environment variable
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<span class="bold"><strong>DB_HOME</strong></span>, or because the utility
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was run in a directory containing a Berkeley DB
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environment).
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In order to avoid environment corruption when using a Berkeley DB
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environment, <span class="command"><strong>db_checkpoint</strong></span> should always be given the chance to detach
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from the environment and exit gracefully. To cause <span class="command"><strong>db_checkpoint</strong></span> to
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release all environment resources and exit cleanly, send it an
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interrupt signal (SIGINT).
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</p>
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<p>
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The <span class="command"><strong>db_checkpoint</strong></span> utility does not attempt to create the Berkeley DB
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shared memory regions if they do not already exist. The application
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that creates the region should be started first, and once the region
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is created, the <span class="command"><strong>db_checkpoint</strong></span> utility should be started.
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</p>
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<p>
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The <a class="xref" href="txncheckpoint.html" title="DB_ENV->txn_checkpoint()">DB_ENV->txn_checkpoint()</a>
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method is the underlying method used by the <span class="command"><strong>db_checkpoint</strong></span> utility. See
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the <span class="command"><strong>db_checkpoint</strong></span> utility source code for an example of using
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<code class="methodname">DB_ENV->txn_checkpoint()</code> in a IEEE/ANSI Std 1003.1 (POSIX) environment.
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</p>
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<p>
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The <span class="command"><strong>db_checkpoint</strong></span> utility exits 0 on success, and >0 if an error
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occurs.
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</p>
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<div class="sect2" 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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<h3 class="title"><a id="id3763870"></a>Environment Variables</h3>
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</div>
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</div>
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</div>
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<div class="sect3" 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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<h4 class="title"><a id="id3764429"></a>DB_HOME</h4>
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</div>
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</div>
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</div>
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<p>
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If the <span class="bold"><strong>-h</strong></span> option is not specified and
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the environment variable DB_HOME is set, it is used as the path of the
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database home, as described in the
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<a class="xref" href="envopen.html" title="DB_ENV->open()">DB_ENV->open()</a> method.
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</p>
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</div>
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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="db_archive.html">Prev</a> </td>
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<td width="20%" align="center">
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<a accesskey="u" href="utilities.html">Up</a>
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</td>
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<td width="40%" align="right"> <a accesskey="n" href="db_deadlock.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">db_archive </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"> db_deadlock</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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