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105 lines
4.9 KiB
HTML
105 lines
4.9 KiB
HTML
<?xml version="1.0" encoding="UTF-8" standalone="no"?>
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<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
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<html xmlns="http://www.w3.org/1999/xhtml">
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<head>
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<meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
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<title>What other services does Berkeley DB provide?</title>
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<link rel="stylesheet" href="gettingStarted.css" type="text/css" />
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<meta name="generator" content="DocBook XSL Stylesheets V1.73.2" />
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<link rel="start" href="index.html" title="Berkeley DB Programmer's Reference Guide" />
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<link rel="up" href="intro.html" title="Chapter 1. Introduction" />
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<link rel="prev" href="intro_need.html" title="Do you need Berkeley DB?" />
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<link rel="next" href="intro_distrib.html" title="What does the Berkeley DB distribution include?" />
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</head>
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<body>
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<div xmlns="" class="navheader">
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<div class="libver">
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<p>Library Version 11.2.5.3</p>
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</div>
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<table width="100%" summary="Navigation header">
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<tr>
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<th colspan="3" align="center">What other services does Berkeley DB provide?</th>
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</tr>
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<tr>
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<td width="20%" align="left"><a accesskey="p" href="intro_need.html">Prev</a> </td>
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<th width="60%" align="center">Chapter 1.
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Introduction
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</th>
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<td width="20%" align="right"> <a accesskey="n" href="intro_distrib.html">Next</a></td>
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</tr>
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</table>
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<hr />
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</div>
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<div class="sect1" lang="en" xml:lang="en">
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<div class="titlepage">
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<div>
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<div>
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<h2 class="title" style="clear: both"><a id="intro_what"></a>What other services does Berkeley DB provide?</h2>
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</div>
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</div>
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</div>
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<p>Berkeley DB also provides core database services to developers. These
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services include:</p>
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<div class="variablelist">
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<dl>
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<dt>
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<span class="term">Page cache management:</span>
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</dt>
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<dd>The page cache provides fast access to a cache of database pages,
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handling the I/O associated with the cache to ensure that dirty pages
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are written back to the file system and that new pages are allocated on
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demand. Applications may use the Berkeley DB shared memory buffer manager to
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serve their own files and pages.</dd>
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<dt>
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<span class="term">Transactions and logging:</span>
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</dt>
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<dd>The transaction and logging systems provide recoverability and atomicity
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for multiple database operations. The transaction system uses two-phase
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locking and write-ahead logging protocols to ensure that database
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operations may be undone or redone in the case of application or system
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failure. Applications may use Berkeley DB transaction and logging subsystems
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to protect their own data structures and operations from application or
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system failure.</dd>
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<dt>
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<span class="term">Locking:</span>
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</dt>
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<dd>The locking system provides multiple reader or single writer access to
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objects. The Berkeley DB access methods use the locking system to acquire
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the right to read or write database pages. Applications may use the
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Berkeley DB locking subsystem to support their own locking needs.</dd>
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</dl>
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</div>
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<p>By combining the page cache, transaction, locking, and logging systems,
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Berkeley DB provides the same services found in much larger, more complex and
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more expensive database systems. Berkeley DB supports multiple simultaneous
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readers and writers and guarantees that all changes are recoverable, even
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in the case of a catastrophic hardware failure during a database update.</p>
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<p>Developers may select some or all of the core database services for any
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access method or database. Therefore, it is possible to choose the
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appropriate storage structure and the right degrees of concurrency and
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recoverability for any application. In addition, some of the subsystems
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(for example, the Locking subsystem) can be called separately from the
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Berkeley DB access method. As a result, developers can integrate non-database
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objects into their transactional applications using Berkeley DB.</p>
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</div>
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<div class="navfooter">
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<hr />
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<table width="100%" summary="Navigation footer">
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<tr>
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<td width="40%" align="left"><a accesskey="p" href="intro_need.html">Prev</a> </td>
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<td width="20%" align="center">
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<a accesskey="u" href="intro.html">Up</a>
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</td>
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<td width="40%" align="right"> <a accesskey="n" href="intro_distrib.html">Next</a></td>
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</tr>
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<tr>
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<td width="40%" align="left" valign="top">Do you need Berkeley DB? </td>
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<td width="20%" align="center">
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<a accesskey="h" href="index.html">Home</a>
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</td>
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<td width="40%" align="right" valign="top"> What does the Berkeley DB distribution include?</td>
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</tr>
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</table>
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</div>
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</body>
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</html>
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