libdb/docs/api_reference/CXX/envlsn_reset.html

205 lines
7.5 KiB
HTML
Raw Normal View History

2011-09-13 17:44:24 +00:00
<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
<title>DbEnv::lsn_reset()</title>
<link rel="stylesheet" href="apiReference.css" type="text/css" />
<meta name="generator" content="DocBook XSL Stylesheets V1.73.2" />
<link rel="start" href="index.html" title="Berkeley DB C++ API Reference" />
<link rel="up" href="env.html" title="Chapter 5.  The DbEnv Handle" />
<link rel="prev" href="envlog_verify.html" title="DbEnv::log_verify()" />
<link rel="next" href="envopen.html" title="DbEnv::open()" />
</head>
<body>
<div xmlns="" class="navheader">
<div class="libver">
<p>Library Version 11.2.5.2</p>
</div>
<table width="100%" summary="Navigation header">
<tr>
<th colspan="3" align="center">DbEnv::lsn_reset()</th>
</tr>
<tr>
<td width="20%" align="left"><a accesskey="p" href="envlog_verify.html">Prev</a> </td>
<th width="60%" align="center">Chapter 5. 
The DbEnv Handle
</th>
<td width="20%" align="right"> <a accesskey="n" href="envopen.html">Next</a></td>
</tr>
</table>
<hr />
</div>
<div class="sect1" lang="en" xml:lang="en">
<div class="titlepage">
<div>
<div>
<h2 class="title" style="clear: both"><a id="envlsn_reset"></a>DbEnv::lsn_reset()</h2>
</div>
</div>
</div>
<pre class="programlisting">#include &lt;db_cxx.h&gt;
int
DbEnv::lsn_reset(const char *file, u_int32_t flags);</pre>
<p>
The <code class="methodname">DbEnv::lsn_reset()</code> method allows database files to be moved from
one transactional database environment to another.
</p>
<p>
Database pages in transactional database environments contain
references to the environment's log files (that is, log sequence
numbers, or LSNs). Copying or moving a database file from one database
environment to another, and then modifying it, can result in data
corruption if the LSNs are not first cleared.
</p>
<p>
Note that LSNs should be reset before moving or copying the database
file into a new database environment, rather than moving or copying
the database file and then resetting the LSNs. Berkeley DB has
consistency checks that may be triggered if an application calls
<code class="methodname">DbEnv::lsn_reset()</code> on a database in a new environment when the
database LSNs still reflect the old environment.
</p>
<p>
The <code class="methodname">DbEnv::lsn_reset()</code> method modifies the physical file, in-place.
Applications should not reset LSNs in files that are currently in use.
</p>
<p>
The <code class="methodname">DbEnv::lsn_reset()</code> method may be called at any time during the
life of the application.
</p>
<p>
The <code class="methodname">DbEnv::lsn_reset()</code> <span>
<span>
method either returns a non-zero error value or throws an
exception that encapsulates a non-zero error value on
failure, and returns 0 on success.
</span>
</span>
</p>
<div class="sect2" lang="en" xml:lang="en">
<div class="titlepage">
<div>
<div>
2011-12-20 00:07:10 +00:00
<h3 class="title"><a id="id3598085"></a>Parameters</h3>
2011-09-13 17:44:24 +00:00
</div>
</div>
</div>
<div class="sect3" lang="en" xml:lang="en">
<div class="titlepage">
<div>
<div>
2011-12-20 00:07:10 +00:00
<h4 class="title"><a id="id3598074"></a>file</h4>
2011-09-13 17:44:24 +00:00
</div>
</div>
</div>
<p>
The name of the physical file in which the LSNs are to be cleared.
</p>
</div>
<div class="sect3" lang="en" xml:lang="en">
<div class="titlepage">
<div>
<div>
2011-12-20 00:07:10 +00:00
<h4 class="title"><a id="id3598171"></a>flags</h4>
2011-09-13 17:44:24 +00:00
</div>
</div>
</div>
<p>
The <span class="bold"><strong>flags</strong></span> parameter must be set to 0
or the following value:
</p>
<div class="itemizedlist">
<ul type="disc">
<li>
<p>
<code class="literal">DB_ENCRYPT</code>
</p>
<p>
The file contains encrypted databases.
</p>
</li>
</ul>
</div>
</div>
</div>
<div class="sect2" lang="en" xml:lang="en">
<div class="titlepage">
<div>
<div>
2011-12-20 00:07:10 +00:00
<h3 class="title"><a id="id3597627"></a>Errors</h3>
2011-09-13 17:44:24 +00:00
</div>
</div>
</div>
<p>
The <code class="methodname">DbEnv::lsn_reset()</code> <span>
<span>
method may fail and throw a <a class="link" href="dbexception.html" title="Chapter 6. The DbException Class">DbException</a>
exception, encapsulating one of the following non-zero errors, or return one
of the following non-zero errors:
</span>
</span>
</p>
<div class="sect3" lang="en" xml:lang="en">
<div class="titlepage">
<div>
<div>
2011-12-20 00:07:10 +00:00
<h4 class="title"><a id="id3598325"></a>EINVAL</h4>
2011-09-13 17:44:24 +00:00
</div>
</div>
</div>
<p>
An invalid flag value or parameter was specified.
</p>
</div>
</div>
<div class="sect2" lang="en" xml:lang="en">
<div class="titlepage">
<div>
<div>
2011-12-20 00:07:10 +00:00
<h3 class="title"><a id="id3598307"></a>Class</h3>
2011-09-13 17:44:24 +00:00
</div>
</div>
</div>
<p>
<a class="link" href="env.html" title="Chapter 5.  The DbEnv Handle">DbEnv</a>
</p>
</div>
<div class="sect2" lang="en" xml:lang="en">
<div class="titlepage">
<div>
<div>
2011-12-20 00:07:10 +00:00
<h3 class="title"><a id="id3598211"></a>See Also</h3>
2011-09-13 17:44:24 +00:00
</div>
</div>
</div>
<p>
<a class="xref" href="env.html#envlist" title="Database Environments and Related Methods">Database Environments and Related Methods</a>
</p>
</div>
</div>
<div class="navfooter">
<hr />
<table width="100%" summary="Navigation footer">
<tr>
<td width="40%" align="left"><a accesskey="p" href="envlog_verify.html">Prev</a> </td>
<td width="20%" align="center">
<a accesskey="u" href="env.html">Up</a>
</td>
<td width="40%" align="right"> <a accesskey="n" href="envopen.html">Next</a></td>
</tr>
<tr>
<td width="40%" align="left" valign="top">DbEnv::log_verify() </td>
<td width="20%" align="center">
<a accesskey="h" href="index.html">Home</a>
</td>
<td width="40%" align="right" valign="top"> DbEnv::open()</td>
</tr>
</table>
</div>
</body>
</html>