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<h2 class="title" style="clear: both"><a id="dbprops"></a>Database Properties</h2>
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<p>You can set database properties using the <code class="classname">DatabaseConfig</code>
class. For each of the properties that you can set, there is a
corresponding getter method. Also, you can always retrieve the
<code class="classname">DatabaseConfig</code> object used by your database using
the <code class="methodname">Database.getConfig()</code> method.</p>
<p>
There are a large number of properties that you can set using this
class (see the javadoc for a complete listing). From the perspective of
this manual, some of the more interesting properties are:
</p>
<div class="itemizedlist">
<ul type="disc">
<li>
<p>
<code class="methodname">DatabaseConfig.setAllowCreate()</code>
</p>
<p>If <code class="literal">true</code>, the database is created when it is
opened. If false, the database open fails if the database does not
exist. This property has no meaning if the database currently exists.
Default is <code class="literal">false</code>.</p>
</li>
<li>
<p>
<code class="methodname">DatabaseConfig.setBtreeComparator()</code>
</p>
<p>Sets the class that is used to compare the keys found on two
database records. This class is used to determine the sort order for
two records in the database. By default, byte for byte comparison is
used.
For more information, see
<span><a class="xref" href="btree.html#comparators" title="Setting Comparison Functions">Setting Comparison Functions</a>.</span>
</p>
</li>
<li>
<p>
<code class="methodname">DatabaseConfig.setDuplicateComparator()</code>
</p>
<p>
Sets the class that is used to compare two duplicate records in
the database. For more information, see
<span><a class="xref" href="btree.html#comparators" title="Setting Comparison Functions">Setting Comparison Functions</a>.</span>
</p>
</li>
<li>
<p>
<code class="methodname">DatabaseConfig.setSortedDuplicates()</code>
</p>
<p>If <code class="literal">true</code>, duplicate records are allowed in the
database. If this value is <code class="literal">false</code>, then putting a duplicate record into the database
results in an error return from the put call.
Note that this property can be set only at database creation time. Default is <code class="literal">false</code>.
</p>
<p>
Note that your database must not support duplicates if it is to be associated with one or more
secondary indices. Secondaries are described in <a class="xref" href="indexes.html" title="Chapter 10. Secondary Databases">Secondary Databases</a>.
</p>
</li>
<li>
<p>
<code class="methodname">DatabaseConfig.setExclusiveCreate()</code>
</p>
<p>If <code class="literal">true</code>, the database open fails if the
database currently exists. That is, the open must result in the
creation of a new database. Default is <code class="literal">false</code>.</p>
</li>
<li>
<p>
<code class="methodname">DatabaseConfig.setReadOnly()</code>
</p>
<p>If true, the database is opened for read activities only.
Default is <code class="literal">false</code>.</p>
</li>
<li>
<p>
<code class="methodname">DatabaseConfig.setTruncate()</code>
</p>
<p>If true, the database is truncated; that is, it is emptied of all
content.
</p>
</li>
<li>
<p>
<code class="methodname">DatabaseConfig.setType()</code>
</p>
<p>Identifies the type of database that you want to create. This
manual will exclusively use <code class="literal">DatabaseType.BTREE</code>.
</p>
</li>
</ul>
</div>
<p>
In addition to these, there are also methods that allow you to
control the IO stream used for error reporting purposes.
These are described later in this manual.
</p>
<p>For example:</p>
<a id="java_db3"></a>
<pre class="programlisting">package db.GettingStarted;
import com.sleepycat.db.Database;
import com.sleepycat.db.DatabaseConfig;
import com.sleepycat.db.DatabaseException;
import com.sleepycat.db.DatabaseType;
import java.io.FileNotFoundException;
...
Database myDatabase = null;
try {
DatabaseConfig dbConfig = new DatabaseConfig();
dbConfig.setAllowCreate(true);
dbConfig.setSortedDuplicates(true);
dbConfig.setType(DatabaseType.BTREE);
myDatabase = new Database("sampleDatabase.db",
null,
dbConfig);
} catch (DatabaseException dbe) {
// Exception handling goes here.
} catch (FileNotFoundException fnfe) {
// Exception handling goes here
}</pre>
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