The path of a directory to be used as the location of logging files.
Log files created by the Log Manager subsystem will be created in this
directory.
</p>
<p>
If no logging directory is specified, log files are created in the
environment home directory. See
<ahref="../../programmer_reference/env_naming.html"class="olink">Berkeley DB File Naming</a> for more
information.
</p>
<p>
For the greatest degree of recoverability from system or application
failure, database files and log files should be located on separate
physical devices.
</p>
<p>
The database environment's logging directory may also be
configured using the environment's <ahref="../../programmer_reference/env_db_config.html#env_db_config.DB_CONFIG"class="olink">DB_CONFIG</a> file. The syntax
of the entry in that file is a single line with the string
"set_lg_dir", one or more whitespace characters, and the directory
name. Because the <ahref="../../programmer_reference/env_db_config.html#env_db_config.DB_CONFIG"class="olink">DB_CONFIG</a> file is read when the database
environment is opened, it will silently overrule configuration
done before that time. Note that if you use this method for your
utilities, then you should set create a <ahref="../../programmer_reference/env_db_config.html#env_db_config.DB_CONFIG"class="olink">DB_CONFIG</a> file and set
the "set_lg_dir" parameter in it.
</p>
<p>
The <codeclass="methodname">DB_ENV->set_lg_dir()</code> method configures operations performed using
the specified <aclass="link"href="env.html"title="Chapter5. The DB_ENV Handle">DB_ENV</a>
handle, not all operations performed on the underlying database
environment.
</p>
<p>
The <codeclass="methodname">DB_ENV->set_lg_dir()</code> method may not be called after the
<aclass="xref"href="envopen.html"title="DB_ENV->open()">DB_ENV->open()</a> method is called.
If the database environment already exists when
<aclass="xref"href="envopen.html"title="DB_ENV->open()">DB_ENV->open()</a> is called, the
information specified to <codeclass="methodname">DB_ENV->set_lg_dir()</code> must be consistent with
the existing environment or corruption can occur.
</p>
<p>
The <codeclass="methodname">DB_ENV->set_lg_dir()</code><span>
<span>
method returns a non-zero error value on failure and 0 on success.