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<h2 class="title" style="clear: both"><a id="coredbclose"></a>Closing Databases</h2>
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<p>
Once you are done using the database, you must close it. You use the
<tt class="methodname">Db::close()</tt>
method to do this.
</p>
<p>
Closing a database causes it to become unusable until it is opened
again. Note that you should make sure that any open cursors are closed
before closing your database. Active cursors during a database
close can cause unexpected results, especially if any of those cursors are
writing to the database. You should always make sure that all your
database accesses have completed before closing your database.
</p>
<p>
Cursors are described in <a href="Cursors.html">Using Cursors</a> later in this manual.
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<p>
Be aware that when you close the last open handle
for a database, then by default its cache is flushed to disk.
This means that any information that has
been modified in the cache is guaranteed to be written to disk when the
last handle is closed. You can manually perform this operation using
the
<tt class="methodname">Db::sync()</tt>
method, but for normal shutdown operations it is not necessary.
For more information about syncing your cache, see
<a href="usingDbt.html#datapersist">Data Persistence</a>.
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<p>The following code fragment illustrates a database close:</p>
<a id="cxx_db2"></a>
<pre class="programlisting">#include <db_cxx.h>
...
Db db(NULL, 0);
// Database open and access operations happen here.
try {
// Close the database
db.close(0);
// DbException is not subclassed from std::exception, so
// need to catch both of these.
} catch(DbException &e) {
// Error handling code goes here
} catch(std::exception &e) {
// Error handling code goes here
} </pre>
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