1<?xml version="1.0" encoding="UTF-8" standalone="no"?> 2<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> 3<html xmlns="http://www.w3.org/1999/xhtml"> 4 <head> 5 <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /> 6 <title>Db::set_q_extentsize()</title> 7 <link rel="stylesheet" href="apiReference.css" type="text/css" /> 8 <meta name="generator" content="DocBook XSL Stylesheets V1.73.2" /> 9 <link rel="start" href="index.html" title="Berkeley DB C++ API Reference" /> 10 <link rel="up" href="db.html" title="Chapter 2. The Db Handle" /> 11 <link rel="prev" href="dbset_priority.html" title="Db::set_priority()" /> 12 <link rel="next" href="dbset_re_delim.html" title="Db::set_re_delim()" /> 13 </head> 14 <body> 15 <div class="navheader"> 16 <table width="100%" summary="Navigation header"> 17 <tr> 18 <th colspan="3" align="center">Db::set_q_extentsize()</th> 19 </tr> 20 <tr> 21 <td width="20%" align="left"><a accesskey="p" href="dbset_priority.html">Prev</a> </td> 22 <th width="60%" align="center">Chapter 2. 23 The Db Handle 24 </th> 25 <td width="20%" align="right"> <a accesskey="n" href="dbset_re_delim.html">Next</a></td> 26 </tr> 27 </table> 28 <hr /> 29 </div> 30 <div class="sect1" lang="en" xml:lang="en"> 31 <div class="titlepage"> 32 <div> 33 <div> 34 <h2 class="title" style="clear: both"><a id="dbset_q_extentsize"></a>Db::set_q_extentsize()</h2> 35 </div> 36 </div> 37 </div> 38 <pre class="programlisting">#include <db_cxx.h> 39 40int 41Db::set_q_extentsize(u_int32_t extentsize); </pre> 42 <p> 43 Set the size of the extents used to hold pages in a Queue database, 44 specified as a number of pages. Each extent is created as a separate 45 physical file. If no extent size is set, the default behavior is to 46 create only a single underlying database file. 47 </p> 48 <p> 49 For information on tuning the extent size, see <a href="../../programmer_reference/rq_conf.html#am_conf_extentsize" class="olink">Selecting a extent size</a>. 50 </p> 51 <p> 52 The <code class="methodname">Db::set_q_extentsize()</code> method configures a database, not only 53 operations performed using the specified <a class="link" href="db.html" title="Chapter 2. The Db Handle">Db</a> 54 handle. 55 </p> 56 <p> 57 The <code class="methodname">Db::set_q_extentsize()</code> method may not be called after the 58 <a class="xref" href="dbopen.html" title="Db::open()">Db::open()</a> method is called. If 59 the database already exists when 60 <a class="xref" href="dbopen.html" title="Db::open()">Db::open()</a> is called, the 61 information specified to <code class="methodname">Db::set_q_extentsize()</code> will be ignored. 62 </p> 63 <p> 64 The <code class="methodname">Db::set_q_extentsize()</code> <span> 65 66 <span> 67 method either returns a non-zero error value or throws an 68 exception that encapsulates a non-zero error value on 69 failure, and returns 0 on success. 70 </span> 71 </span> 72 </p> 73 <div class="sect2" lang="en" xml:lang="en"> 74 <div class="titlepage"> 75 <div> 76 <div> 77 <h3 class="title"><a id="id1649806"></a>Parameters</h3> 78 </div> 79 </div> 80 </div> 81 <div class="sect3" lang="en" xml:lang="en"> 82 <div class="titlepage"> 83 <div> 84 <div> 85 <h4 class="title"><a id="id1650581"></a>extentsize</h4> 86 </div> 87 </div> 88 </div> 89 <p> 90 The <span class="bold"><strong>extentsize</strong></span> parameter is the 91 number of pages in a Queue database extent. 92 </p> 93 </div> 94 </div> 95 <div class="sect2" lang="en" xml:lang="en"> 96 <div class="titlepage"> 97 <div> 98 <div> 99 <h3 class="title"><a id="id1649337"></a>Errors</h3> 100 </div> 101 </div> 102 </div> 103 <p> 104 The <code class="methodname">Db::set_q_extentsize()</code> <span> 105 106 <span> 107 method may fail and throw a <a class="link" href="dbexception.html" title="Chapter 6. The DbException Class">DbException</a> 108 exception, encapsulating one of the following non-zero errors, or return one 109 of the following non-zero errors: 110 </span> 111 </span> 112 </p> 113 <div class="sect3" lang="en" xml:lang="en"> 114 <div class="titlepage"> 115 <div> 116 <div> 117 <h4 class="title"><a id="id1650517"></a>EINVAL</h4> 118 </div> 119 </div> 120 </div> 121 <p> 122 If the method was called after <a class="xref" href="dbopen.html" title="Db::open()">Db::open()</a> 123 was called; or if an invalid flag value or parameter was specified. 124 </p> 125 </div> 126 </div> 127 <div class="sect2" lang="en" xml:lang="en"> 128 <div class="titlepage"> 129 <div> 130 <div> 131 <h3 class="title"><a id="id1650518"></a>Class</h3> 132 </div> 133 </div> 134 </div> 135 <p> 136 <a class="link" href="db.html" title="Chapter 2. The Db Handle">Db</a> 137 </p> 138 </div> 139 <div class="sect2" lang="en" xml:lang="en"> 140 <div class="titlepage"> 141 <div> 142 <div> 143 <h3 class="title"><a id="id1650785"></a>See Also</h3> 144 </div> 145 </div> 146 </div> 147 <p> 148 <a class="xref" href="db.html#dblist" title="Database and Related Methods">Database and Related Methods</a> 149 </p> 150 </div> 151 </div> 152 <div class="navfooter"> 153 <hr /> 154 <table width="100%" summary="Navigation footer"> 155 <tr> 156 <td width="40%" align="left"><a accesskey="p" href="dbset_priority.html">Prev</a> </td> 157 <td width="20%" align="center"> 158 <a accesskey="u" href="db.html">Up</a> 159 </td> 160 <td width="40%" align="right"> <a accesskey="n" href="dbset_re_delim.html">Next</a></td> 161 </tr> 162 <tr> 163 <td width="40%" align="left" valign="top">Db::set_priority() </td> 164 <td width="20%" align="center"> 165 <a accesskey="h" href="index.html">Home</a> 166 </td> 167 <td width="40%" align="right" valign="top"> Db::set_re_delim()</td> 168 </tr> 169 </table> 170 </div> 171 </body> 172</html> 173