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<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
  <head>
    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
    <title>Flushing the database cache</title>
    <link rel="stylesheet" href="gettingStarted.css" type="text/css" />
    <meta name="generator" content="DocBook XSL Stylesheets V1.73.2" />
    <link rel="start" href="index.html" title="Berkeley DB Programmer's Reference Guide" />
    <link rel="up" href="am.html" title="Chapter 3.  Access Method Operations" />
    <link rel="prev" href="am_verify.html" title="Database verification and salvage" />
    <link rel="next" href="am_close.html" title="Database close" />
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    <div xmlns="" class="navheader">
      <div class="libver">
        <p>Library Version 11.2.5.3</p>
      </div>
      <table width="100%" summary="Navigation header">
        <tr>
          <th colspan="3" align="center">Flushing the database cache</th>
        </tr>
        <tr>
          <td width="20%" align="left"><a accesskey="p" href="am_verify.html">Prev</a> </td>
          <th width="60%" align="center">Chapter 3. 
		Access Method Operations
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          <td width="20%" align="right"> <a accesskey="n" href="am_close.html">Next</a></td>
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    <div class="sect1" lang="en" xml:lang="en">
      <div class="titlepage">
        <div>
          <div>
            <h2 class="title" style="clear: both"><a id="am_sync"></a>Flushing the database cache</h2>
          </div>
        </div>
      </div>
      <p>The <a href="../api_reference/C/dbsync.html" class="olink">DB-&gt;sync()</a> method flushes all modified records from the database
cache to disk.</p>
      <p>
        <span class="bold">
          <strong>It is important to understand that flushing cached information
to disk only minimizes the window of opportunity for corrupted data, it
does not eliminate the possibility.</strong>
        </span>
      </p>
      <p>While unlikely, it is possible for database corruption to happen if a
system or application crash occurs while writing data to the database. To
ensure that database corruption never occurs, applications must either:</p>
      <div class="itemizedlist">
        <ul type="disc">
          <li>Use transactions and logging with automatic recovery.</li>
          <li>Use logging and application-specific recovery.</li>
          <li>Edit a copy of the database, and, once all applications
using the database have successfully called <a href="../api_reference/C/dbclose.html" class="olink">DB-&gt;close()</a>, use
system operations (for example, the POSIX rename system call) to
atomically replace the original database with the updated copy.</li>
        </ul>
      </div>
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          <td width="40%" align="left" valign="top">Database verification and salvage </td>
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            <a accesskey="h" href="index.html">Home</a>
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          <td width="40%" align="right" valign="top"> Database close</td>
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