<?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>DB_ENV->log_verify()</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 DB_ENV Handle" />
<link rel="prev" href="envget_verbose.html" title="DB_ENV->get_verbose()" />
<link rel="next" href="envlsn_reset.html" title="DB_ENV->lsn_reset()" />
</head>
<body>
<div class="navheader">
<table width="100%" summary="Navigation header">
<tr>
<th colspan="3" align="center">DB_ENV->log_verify()</th>
</tr>
<tr>
<td width="20%" align="left"><a accesskey="p" href="envget_verbose.html">Prev</a> </td>
<th width="60%" align="center">Chapter 5.
The DB_ENV Handle
</th>
<td width="20%" align="right"> <a accesskey="n" href="envlsn_reset.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="envlog_verify"></a>DB_ENV->log_verify()</h2>
</div>
</div>
</div>
<pre class="programlisting">#include <db.h>
int
DB_ENV->log_verify(DB_ENV *dbenv, const DB_LOG_VERIFY_CONFIG *config);
</pre>
<p>
The <code class="methodname">DB_ENV->log_verify()</code> method verifies the integrity
of the log records of an environment and writes both error
and normal messages to the error/message output facility of the database environment handle.
</p>
<p>
The <code class="methodname">DB_ENV->log_verify()</code> method does not perform the
locking function, even in Berkeley DB environments that are configured with a
locking subsystem. Because this function does not access any database files, you can call it even when the environment has other threads of control
attached and running.
</p>
<p>
The <code class="methodname">DB_ENV->log_verify()</code> method is the underlying method used by the
<code class="methodname">DB_ENV-> db_log_verify</code> utility. See the
<code class="methodname">DB_ENV-> db_log_verify</code> utility
source code for an example of using <code class="methodname">DB_ENV->log_verify()</code> in a IEEE/ANSI Std
1003.1 (POSIX) environment.
</p>
<p>
The <code class="methodname">DB_ENV->log_verify()</code> method returns DB_LOG_VERIFY_BAD when either log errors
are detected or the internal data storage layer does not work.
It returns EINVAL if you specify wrong configurations.
Unless otherwise specified, the <code class="methodname">DB_ENV->log_verify()</code>
<span>
<span>
method returns a non-zero error value on failure and 0 on success.
</span>
</span>
</p>
<div class="sect2" lang="en" xml:lang="en">
<div class="titlepage">
<div>
<div>
<h3 class="title"><a id="id3663280"></a>Parameters</h3>
</div>
</div>
</div>
<div class="sect3" lang="en" xml:lang="en">
<div class="titlepage">
<div>
<div>
<h4 class="title"><a id="id3663441"></a>config </h4>
</div>
</div>
</div>
<p>
The configuration parameter of type DB_LOG_VERIFY_CONFIG is for the verification of log files.
A struct variable of this type must be memset to 0 before setting any configurations to it.
</p>
</div>
</div>
<div class="sect2" lang="en" xml:lang="en">
<div class="titlepage">
<div>
<div>
<h3 class="title"><a id="id3662431"></a>DB_LOG_VERIFY_CONFIG members</h3>
</div>
</div>
</div>
<pre class="programlisting">
struct __db_logvrfy_config {
int continue_after_fail, verbose;
u_int32_t cachesize;
const char *temp_envhome;
const char *dbfile, *dbname;
DB_LSN start_lsn, end_lsn;
time_t start_time, end_time;
};
</pre>
<div class="sect3" lang="en" xml:lang="en">
<div class="titlepage">
<div>
<div>
<h4 class="title"><a id="id3663460"></a>continue_after_fail</h4>
</div>
</div>
</div>
<p>
The <span class="bold"><strong>continue_after_fail</strong></span> parameter specifies whether or not continue the verification process when an error in the log is detected.
</p>
</div>
<div class="sect3" lang="en" xml:lang="en">
<div class="titlepage">
<div>
<div>
<h4 class="title"><a id="id3662906"></a>verbose</h4>
</div>
</div>
</div>
<p>
The <span class="bold"><strong>verbose</strong></span> parameter specifies whether or not to display verbose output during the verification process.
</p>
</div>
<div class="sect3" lang="en" xml:lang="en">
<div class="titlepage">
<div>
<div>
<h4 class="title"><a id="id3663067"></a>cachesize</h4>
</div>
</div>
</div>
<p>
The <span class="bold"><strong>cachesize</strong></span> parameter specifies the size of the cache of the temporary internal environment in bytes.
</p>
</div>
<div class="sect3" lang="en" xml:lang="en">
<div class="titlepage">
<div>
<div>
<h4 class="title"><a id="id3663327"></a> temp_envhome</h4>
</div>
</div>
</div>
<p>
The <span class="bold"><strong>temp_envhome</strong></span> parameter is the home directory of the temporary database environment that is used internally during the verification. It can be NULL, meaning the environment and all databases are in-memory.
</p>
</div>
<div class="sect3" lang="en" xml:lang="en">
<div class="titlepage">
<div>
<div>
<h4 class="title"><a id="id3663382"></a>dbfile</h4>
</div>
</div>
</div>
<p>
The <span class="bold"><strong>dbfile</strong></span> parameter specifies that for log records involving a database file, only those related to this database file are verified. Log records not involving database files are verified regardless of this parameter.
</p>
</div>
<div class="sect3" lang="en" xml:lang="en">
<div class="titlepage">
<div>
<div>
<h4 class="title"><a id="id3663442"></a>dbname</h4>
</div>
</div>
</div>
<p>
The <span class="bold"><strong>dbname</strong></span> parameter specifies that for log records involving a database file, only those related to this database file are verified. Log records not involving database files are verified regardless of this parameter.
</p>
</div>
<div class="sect3" lang="en" xml:lang="en">
<div class="titlepage">
<div>
<div>
<h4 class="title"><a id="id3663488"></a>start_lsn and end_lsn </h4>
</div>
</div>
</div>
<p>
The <span class="bold"><strong>start_lsn</strong></span>
and <span class="bold"><strong>end_lsn </strong></span> parameters specify the range of log records from the entire log set, that must be verified. Either of them can be [0][0], to specify an open ended range. If both of them are [0][0] (by default) the entire log is verified.
</p>
</div>
<div class="sect3" lang="en" xml:lang="en">
<div class="titlepage">
<div>
<div>
<h4 class="title"><a id="id3663510"></a>start_time and end_time </h4>
</div>
</div>
</div>
<p>
The <span class="bold"><strong>start_time</strong></span>
and <span class="bold"><strong>end_time </strong></span>
parameters specify range of log records from the entire log set that must be verified for a time range. Either of them can be 0, to specify an open ended range. If both of them are 0 (by default), the entire log is verified.
</p>
<p>
Note that the time range specified is not precise, because such a time range is converted to an lsn range based on the time points we know from transaction commits and checkpoints.
</p>
<p>
You can specify either an lsn range or a time range. You can neither specify both nor specify an lsn and a time as a range.
</p>
</div>
</div>
<div class="sect2" lang="en" xml:lang="en">
<div class="titlepage">
<div>
<div>
<h3 class="title"><a id="id3663532"></a>Environment Variables</h3>
</div>
</div>
</div>
<p>
If the database is opened within a database environment, the
environment variable <code class="literal">DB_HOME</code> can be used as the path of the
database environment home.
</p>
</div>
<div class="sect2" lang="en" xml:lang="en">
<div class="titlepage">
<div>
<div>
<h3 class="title"><a id="id3663547"></a>Errors</h3>
</div>
</div>
</div>
<p>
The <code class="methodname">DB_ENV->log_verify()</code> <span>
<span>
method may fail and return one of the following non-zero errors:
</span>
</span>
</p>
<p>EINVAL or DB_LOG_VERIFY_BAD.</p>
</div>
<div class="sect2" lang="en" xml:lang="en">
<div class="titlepage">
<div>
<div>
<h3 class="title"><a id="id3663604"></a>Class</h3>
</div>
</div>
</div>
<p>
<a class="link" href="env.html" title="Chapter 5. The DB_ENV Handle">DB_ENV</a>
</p>
</div>
<div class="sect2" lang="en" xml:lang="en">
<div class="titlepage">
<div>
<div>
<h3 class="title"><a id="id3663625"></a>See Also</h3>
</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="envget_verbose.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="envlsn_reset.html">Next</a></td>
</tr>
<tr>
<td width="40%" align="left" valign="top">DB_ENV->get_verbose() </td>
<td width="20%" align="center">
<a accesskey="h" href="index.html">Home</a>
</td>
<td width="40%" align="right" valign="top"> DB_ENV->lsn_reset()</td>
</tr>
</table>
</div>
</body>
</html>
