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<title>Berkeley DB: DbEnv.set_data_dir</title>
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<h1>DbEnv.set_data_dir</h1>
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<h3><pre>
import com.sleepycat.db.*;
<p>
public void set_data_dir(String dir)
throws DbException;
</pre></h3>
<h1>Description</h1>
<p>Set the path of a directory to be used as the location of the access
method database files. Paths specified to the <a href="../api_java/db_open.html">Db.open</a> function
will be searched relative to this path. Paths set using this interface
are additive, and specifying more than one will result in each specified
directory being searched for database files. If any directories are
specified, created database files will always be created in the first path
specified.
<p>If no database directories are specified, database files can exist only
in the environment home directory. See <a href="../ref/env/naming.html">Berkeley DB File Naming</a> for more information.
<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>The DbEnv.set_data_dir method configures operations performed using the specified
<a href="../api_java/env_class.html">DbEnv</a> handle, not all operations performed on the underlying
database environment.
<p>The DbEnv.set_data_dir interface may not be called after the <a href="../api_java/env_open.html">DbEnv.open</a>
interface is called.
If the database environment already exists when
<a href="../api_java/env_open.html">DbEnv.open</a> is called, the information specified to DbEnv.set_data_dir
must be consistent with the existing environment or corruption can
occur.
<p>The DbEnv.set_data_dir method throws an exception that encapsulates a non-zero error value on
failure.
<p>The database environment's data directory may also be set using the environment's
<b>DB_CONFIG</b> file. The syntax of the entry in that file is a
single line with the string "set_data_dir", one or more whitespace characters,
and the directory name. Because the <b>DB_CONFIG</b> file is read when the database
environment is opened, it will silently overrule configuration done
before that time.
<h1>Errors</h1>
<p>The DbEnv.set_data_dir method may fail and throw an exception encapsulating a non-zero error for the following conditions:
<p><dl compact>
<p><dt>EINVAL<dd>An invalid flag value or parameter was specified.
<p>Called after <a href="../api_java/env_open.html">DbEnv.open</a> was called.
</dl>
<p>The DbEnv.set_data_dir method may fail and throw an exception for errors specified for other Berkeley DB and C library or system methods.
If a catastrophic error has occurred, the DbEnv.set_data_dir method may fail and
throw a <a href="../api_java/runrec_class.html">DbRunRecoveryException</a>,
in which case all subsequent Berkeley DB calls will fail in the same way.
<h1>Class</h1>
<a href="../api_java/env_class.html">DbEnv</a>
<h1>See Also</h1>
<a href="../api_java/env_list.html">Database Environments and Related Methods</a>
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