2011-09-13 17:44:24 +00:00
|
|
|
|
<?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>DB->set_priority()</title>
|
|
|
|
|
|
<link rel="stylesheet" href="apiReference.css" type="text/css" />
|
|
|
|
|
|
<meta name="generator" content="DocBook XSL Stylesheets V1.73.2" />
|
|
|
|
|
|
<link rel="start" href="index.html" title="Berkeley DB C API Reference" />
|
|
|
|
|
|
<link rel="up" href="db.html" title="Chapter 2. The DB Handle" />
|
|
|
|
|
|
<link rel="prev" href="dbset_partition_dirs.html" title="DB->set_partition_dirs()" />
|
|
|
|
|
|
<link rel="next" href="dbset_q_extentsize.html" title="DB->set_q_extentsize()" />
|
|
|
|
|
|
</head>
|
|
|
|
|
|
<body>
|
|
|
|
|
|
<div xmlns="" class="navheader">
|
|
|
|
|
|
<div class="libver">
|
2012-11-14 21:35:20 +00:00
|
|
|
|
<p>Library Version 11.2.5.3</p>
|
2011-09-13 17:44:24 +00:00
|
|
|
|
</div>
|
|
|
|
|
|
<table width="100%" summary="Navigation header">
|
|
|
|
|
|
<tr>
|
|
|
|
|
|
<th colspan="3" align="center">DB->set_priority()</th>
|
|
|
|
|
|
</tr>
|
|
|
|
|
|
<tr>
|
|
|
|
|
|
<td width="20%" align="left"><a accesskey="p" href="dbset_partition_dirs.html">Prev</a> </td>
|
|
|
|
|
|
<th width="60%" align="center">Chapter 2.
|
|
|
|
|
|
The DB Handle
|
|
|
|
|
|
</th>
|
|
|
|
|
|
<td width="20%" align="right"> <a accesskey="n" href="dbset_q_extentsize.html">Next</a></td>
|
|
|
|
|
|
</tr>
|
|
|
|
|
|
</table>
|
|
|
|
|
|
<hr />
|
|
|
|
|
|
</div>
|
|
|
|
|
|
<div class="sect1" lang="en" xml:lang="en">
|
|
|
|
|
|
<div class="titlepage">
|
|
|
|
|
|
<div>
|
|
|
|
|
|
<div>
|
|
|
|
|
|
<h2 class="title" style="clear: both"><a id="dbset_priority"></a>DB->set_priority()</h2>
|
|
|
|
|
|
</div>
|
|
|
|
|
|
</div>
|
|
|
|
|
|
</div>
|
|
|
|
|
|
<pre class="programlisting">#include <db.h>
|
|
|
|
|
|
|
|
|
|
|
|
int
|
|
|
|
|
|
DB->set_priority(DB *db, DB_CACHE_PRIORITY priority); </pre>
|
|
|
|
|
|
<p>
|
|
|
|
|
|
Set the cache priority for pages referenced by the
|
|
|
|
|
|
<a class="link" href="db.html" title="Chapter 2. The DB Handle">DB</a> handle.
|
|
|
|
|
|
</p>
|
|
|
|
|
|
<p>
|
|
|
|
|
|
The priority of a page biases the replacement algorithm to be more or
|
|
|
|
|
|
less likely to discard a page when space is needed in the buffer pool.
|
|
|
|
|
|
The bias is temporary, and pages will eventually be discarded if they
|
|
|
|
|
|
are not referenced again. The <code class="methodname">DB->set_priority()</code> method is only
|
|
|
|
|
|
advisory, and does not guarantee pages will be treated in a specific
|
|
|
|
|
|
way.
|
|
|
|
|
|
</p>
|
|
|
|
|
|
<p>
|
|
|
|
|
|
The <code class="methodname">DB->set_priority()</code> method may be called at any time during the
|
|
|
|
|
|
life of the application.
|
|
|
|
|
|
</p>
|
|
|
|
|
|
<p>
|
|
|
|
|
|
The <code class="methodname">DB->set_priority()</code> <span>
|
|
|
|
|
|
<span>
|
|
|
|
|
|
method returns a non-zero error value on failure and 0 on success.
|
|
|
|
|
|
</span>
|
|
|
|
|
|
|
|
|
|
|
|
</span>
|
|
|
|
|
|
</p>
|
|
|
|
|
|
<div class="sect2" lang="en" xml:lang="en">
|
|
|
|
|
|
<div class="titlepage">
|
|
|
|
|
|
<div>
|
|
|
|
|
|
<div>
|
2012-11-14 21:35:20 +00:00
|
|
|
|
<h3 class="title"><a id="idp58502944"></a>Parameters</h3>
|
2011-09-13 17:44:24 +00:00
|
|
|
|
</div>
|
|
|
|
|
|
</div>
|
|
|
|
|
|
</div>
|
|
|
|
|
|
<div class="sect3" lang="en" xml:lang="en">
|
|
|
|
|
|
<div class="titlepage">
|
|
|
|
|
|
<div>
|
|
|
|
|
|
<div>
|
2012-11-14 21:35:20 +00:00
|
|
|
|
<h4 class="title"><a id="idp58503160"></a>priority</h4>
|
2011-09-13 17:44:24 +00:00
|
|
|
|
</div>
|
|
|
|
|
|
</div>
|
|
|
|
|
|
</div>
|
|
|
|
|
|
<p>
|
|
|
|
|
|
The <span class="bold"><strong>priority</strong></span> parameter must be set to
|
|
|
|
|
|
one of the following values:
|
|
|
|
|
|
</p>
|
|
|
|
|
|
<div class="itemizedlist">
|
|
|
|
|
|
<ul type="disc">
|
|
|
|
|
|
<li>
|
|
|
|
|
|
<p><a id="set_priority_DB_PRIORITY_VERY_LOW"></a>
|
|
|
|
|
|
<code class="literal">DB_PRIORITY_VERY_LOW</code>
|
|
|
|
|
|
</p>
|
|
|
|
|
|
<p>
|
|
|
|
|
|
The lowest priority: pages are the most likely to be discarded.
|
|
|
|
|
|
</p>
|
|
|
|
|
|
</li>
|
|
|
|
|
|
<li>
|
|
|
|
|
|
<p><a id="set_priority_DB_PRIORITY_LOW"></a>
|
|
|
|
|
|
<code class="literal">DB_PRIORITY_LOW</code>
|
|
|
|
|
|
</p>
|
|
|
|
|
|
<p>
|
|
|
|
|
|
The next lowest priority.
|
|
|
|
|
|
</p>
|
|
|
|
|
|
</li>
|
|
|
|
|
|
<li>
|
|
|
|
|
|
<p><a id="set_priority_DB_PRIORITY_DEFAULT"></a>
|
|
|
|
|
|
<code class="literal">DB_PRIORITY_DEFAULT</code>
|
|
|
|
|
|
</p>
|
|
|
|
|
|
<p>
|
|
|
|
|
|
The default priority.
|
|
|
|
|
|
</p>
|
|
|
|
|
|
</li>
|
|
|
|
|
|
<li>
|
|
|
|
|
|
<p><a id="set_priority_DB_PRIORITY_HIGH"></a>
|
|
|
|
|
|
<code class="literal">DB_PRIORITY_HIGH</code>
|
|
|
|
|
|
</p>
|
|
|
|
|
|
<p>
|
|
|
|
|
|
The next highest priority.
|
|
|
|
|
|
</p>
|
|
|
|
|
|
</li>
|
|
|
|
|
|
<li>
|
|
|
|
|
|
<p><a id="set_priority_DB_PRIORITY_VERY_HIGH"></a>
|
|
|
|
|
|
<code class="literal">DB_PRIORITY_VERY_HIGH</code>
|
|
|
|
|
|
</p>
|
|
|
|
|
|
<p>
|
|
|
|
|
|
The highest priority: pages are the least likely to be discarded.
|
|
|
|
|
|
</p>
|
|
|
|
|
|
</li>
|
|
|
|
|
|
</ul>
|
|
|
|
|
|
</div>
|
|
|
|
|
|
</div>
|
|
|
|
|
|
</div>
|
|
|
|
|
|
<div class="sect2" lang="en" xml:lang="en">
|
|
|
|
|
|
<div class="titlepage">
|
|
|
|
|
|
<div>
|
|
|
|
|
|
<div>
|
2012-11-14 21:35:20 +00:00
|
|
|
|
<h3 class="title"><a id="idp58519072"></a>Class</h3>
|
2011-09-13 17:44:24 +00:00
|
|
|
|
</div>
|
|
|
|
|
|
</div>
|
|
|
|
|
|
</div>
|
|
|
|
|
|
<p>
|
|
|
|
|
|
<a class="link" href="db.html" title="Chapter 2. The DB Handle">DB</a>
|
|
|
|
|
|
</p>
|
|
|
|
|
|
</div>
|
|
|
|
|
|
<div class="sect2" lang="en" xml:lang="en">
|
|
|
|
|
|
<div class="titlepage">
|
|
|
|
|
|
<div>
|
|
|
|
|
|
<div>
|
2012-11-14 21:35:20 +00:00
|
|
|
|
<h3 class="title"><a id="idp58486456"></a>See Also</h3>
|
2011-09-13 17:44:24 +00:00
|
|
|
|
</div>
|
|
|
|
|
|
</div>
|
|
|
|
|
|
</div>
|
|
|
|
|
|
<p>
|
|
|
|
|
|
<a class="xref" href="db.html#dblist" title="Database and Related Methods">Database and Related Methods</a>
|
|
|
|
|
|
</p>
|
|
|
|
|
|
</div>
|
|
|
|
|
|
</div>
|
|
|
|
|
|
<div class="navfooter">
|
|
|
|
|
|
<hr />
|
|
|
|
|
|
<table width="100%" summary="Navigation footer">
|
|
|
|
|
|
<tr>
|
|
|
|
|
|
<td width="40%" align="left"><a accesskey="p" href="dbset_partition_dirs.html">Prev</a> </td>
|
|
|
|
|
|
<td width="20%" align="center">
|
|
|
|
|
|
<a accesskey="u" href="db.html">Up</a>
|
|
|
|
|
|
</td>
|
|
|
|
|
|
<td width="40%" align="right"> <a accesskey="n" href="dbset_q_extentsize.html">Next</a></td>
|
|
|
|
|
|
</tr>
|
|
|
|
|
|
<tr>
|
|
|
|
|
|
<td width="40%" align="left" valign="top">DB->set_partition_dirs() </td>
|
|
|
|
|
|
<td width="20%" align="center">
|
|
|
|
|
|
<a accesskey="h" href="index.html">Home</a>
|
|
|
|
|
|
</td>
|
|
|
|
|
|
<td width="40%" align="right" valign="top"> DB->set_q_extentsize()</td>
|
|
|
|
|
|
</tr>
|
|
|
|
|
|
</table>
|
|
|
|
|
|
</div>
|
|
|
|
|
|
</body>
|
|
|
|
|
|
</html>
|
