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13<td><b><dl><dt>Berkeley DB Reference Guide:<dd>Access Methods</dl></b></td>
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16<p align=center><b>Database close</b></p>
17<p>The <a href="../../api_c/db_close.html">DB-&gt;close</a> method closes the <a href="../../api_c/db_class.html">DB</a> database handle.  By
18default, <a href="../../api_c/db_close.html">DB-&gt;close</a> also flushes all modified records from the
19database cache to disk.</p>
20<p>There is one flag that you can set to customize <a href="../../api_c/db_close.html">DB-&gt;close</a>:</p>
21<br>
22<b><a href="../../api_c/db_close.html#DB_NOSYNC">DB_NOSYNC</a></b><ul compact><li>Do not flush cached information to disk.</ul>
23<br>
24<b>It is important to understand that flushing cached information
25to disk only minimizes the window of opportunity for corrupted data, it
26does not eliminate the possibility.</b>
27<p>While unlikely, it is possible for database corruption to happen if a
28system or application crash occurs while writing data to the database. To
29ensure that database corruption never occurs, applications must either:</p>
30<p><ul type=disc>
31<li>Use transactions and logging with automatic recovery.
32<li>Use logging and application-specific recovery.
33<li>Edit a copy of the database, and, once all applications
34using the database have successfully called <a href="../../api_c/db_close.html">DB-&gt;close</a>, use
35system operations (for example, the POSIX rename system call) to
36atomically replace the original database with the updated copy.
37</ul>
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