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>DbEnv::set_lg_regionmax()</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="lsn.html" title="Chapter 8. The DbLsn Handle" /> 11 <link rel="prev" href="envset_lg_max.html" title="DbEnv::set_lg_max()" /> 12 <link rel="next" href="logc.html" title="The DbLogc Handle" /> 13 </head> 14 <body> 15 <div class="navheader"> 16 <table width="100%" summary="Navigation header"> 17 <tr> 18 <th colspan="3" align="center">DbEnv::set_lg_regionmax()</th> 19 </tr> 20 <tr> 21 <td width="20%" align="left"><a accesskey="p" href="envset_lg_max.html">Prev</a> </td> 22 <th width="60%" align="center">Chapter 8. 23 The DbLsn Handle 24 </th> 25 <td width="20%" align="right"> <a accesskey="n" href="logc.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="envset_lg_regionmax"></a>DbEnv::set_lg_regionmax()</h2> 35 </div> 36 </div> 37 </div> 38 <pre class="programlisting">#include <db_cxx.h> 39 40int 41DbEnv::set_lg_regionmax(u_int32_t lg_regionmax); </pre> 42 <p> 43 Set the size of the underlying logging area of the Berkeley DB 44 environment, in bytes. By default, or if the value is set to 0, the 45 minimum region size is used, approximately 128KB. The log region is 46 used to store filenames, and so may need to be increased in size if a 47 large number of files will be opened and registered with the specified 48 Berkeley DB environment's log manager. 49 </p> 50 <p> 51 The database environment's log region size may also be configured 52 using the environment's <a href="../../programmer_reference/env_db_config.html#env_db_config.DB_CONFIG" class="olink">DB_CONFIG</a> file. The 53 syntax of the entry in that file is a single line with the string 54 "set_lg_regionmax", one or more whitespace characters, and the size in 55 bytes. Because the <a href="../../programmer_reference/env_db_config.html#env_db_config.DB_CONFIG" class="olink">DB_CONFIG</a> file is 56 read when the database environment is opened, it will silently 57 overrule configuration done before that time. 58 </p> 59 <p> 60 The <code class="methodname">DbEnv::set_lg_regionmax()</code> method configures a database 61 environment, not only operations performed using the specified 62 <a class="link" href="env.html" title="Chapter 5. The DbEnv Handle">DbEnv</a> handle. 63 </p> 64 <p> 65 The <code class="methodname">DbEnv::set_lg_regionmax()</code> method may not be called after the 66 <a class="xref" href="envopen.html" title="DbEnv::open()">DbEnv::open()</a> method is 67 called. If the database environment already exists when 68 <a class="xref" href="envopen.html" title="DbEnv::open()">DbEnv::open()</a> is called, the 69 information specified to <code class="methodname">DbEnv::set_lg_regionmax()</code> will be ignored. 70 </p> 71 <p> 72 The <code class="methodname">DbEnv::set_lg_regionmax()</code> <span> 73 74 <span> 75 method either returns a non-zero error value or throws an 76 exception that encapsulates a non-zero error value on 77 failure, and returns 0 on success. 78 </span> 79 </span> 80 </p> 81 <div class="sect2" lang="en" xml:lang="en"> 82 <div class="titlepage"> 83 <div> 84 <div> 85 <h3 class="title"><a id="id1688091"></a>Parameters</h3> 86 </div> 87 </div> 88 </div> 89 <div class="sect3" lang="en" xml:lang="en"> 90 <div class="titlepage"> 91 <div> 92 <div> 93 <h4 class="title"><a id="id1688518"></a>lg_regionmax</h4> 94 </div> 95 </div> 96 </div> 97 <p> 98 The <span class="bold"><strong>lg_regionmax</strong></span> parameter is the 99 size of the logging area in the Berkeley DB environment, in bytes. 100 </p> 101 </div> 102 </div> 103 <div class="sect2" lang="en" xml:lang="en"> 104 <div class="titlepage"> 105 <div> 106 <div> 107 <h3 class="title"><a id="id1688728"></a>Errors</h3> 108 </div> 109 </div> 110 </div> 111 <p> 112 The <code class="methodname">DbEnv::set_lg_regionmax()</code> <span> 113 114 <span> 115 method may fail and throw a <a class="link" href="dbexception.html" title="Chapter 6. The DbException Class">DbException</a> 116 exception, encapsulating one of the following non-zero errors, or return one 117 of the following non-zero errors: 118 </span> 119 </span> 120 </p> 121 <div class="sect3" lang="en" xml:lang="en"> 122 <div class="titlepage"> 123 <div> 124 <div> 125 <h4 class="title"><a id="id1688401"></a>EINVAL</h4> 126 </div> 127 </div> 128 </div> 129 <p> 130 If the method was called after <a class="xref" href="envopen.html" title="DbEnv::open()">DbEnv::open()</a> 131 was called; or if an invalid flag value or parameter was specified. 132 </p> 133 </div> 134 </div> 135 <div class="sect2" lang="en" xml:lang="en"> 136 <div class="titlepage"> 137 <div> 138 <div> 139 <h3 class="title"><a id="id1688395"></a>Class</h3> 140 </div> 141 </div> 142 </div> 143 <p> 144 <a class="link" href="env.html" title="Chapter 5. The DbEnv Handle">DbEnv</a>, 145 <a class="link" href="logc.html" title="The DbLogc Handle">DbLogc</a>, 146 <a class="link" href="lsn.html" title="Chapter 8. The DbLsn Handle">DbLsn</a> 147 </p> 148 </div> 149 <div class="sect2" lang="en" xml:lang="en"> 150 <div class="titlepage"> 151 <div> 152 <div> 153 <h3 class="title"><a id="id1688519"></a>See Also</h3> 154 </div> 155 </div> 156 </div> 157 <p> 158 <a class="xref" href="lsn.html#loglist" title="Logging Subsystem and Related Methods">Logging Subsystem and Related Methods</a> 159 </p> 160 </div> 161 </div> 162 <div class="navfooter"> 163 <hr /> 164 <table width="100%" summary="Navigation footer"> 165 <tr> 166 <td width="40%" align="left"><a accesskey="p" href="envset_lg_max.html">Prev</a> </td> 167 <td width="20%" align="center"> 168 <a accesskey="u" href="lsn.html">Up</a> 169 </td> 170 <td width="40%" align="right"> <a accesskey="n" href="logc.html">Next</a></td> 171 </tr> 172 <tr> 173 <td width="40%" align="left" valign="top">DbEnv::set_lg_max() </td> 174 <td width="20%" align="center"> 175 <a accesskey="h" href="index.html">Home</a> 176 </td> 177 <td width="40%" align="right" valign="top"> 178 The DbLogc Handle 179 </td> 180 </tr> 181 </table> 182 </div> 183 </body> 184</html> 185