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>Chapter��5.�� The DbEnv Handle</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="index.html" title="Berkeley DB C++ API Reference" /> 11 <link rel="prev" href="dbmultiplerecnodatabuilder.html" title="DbMultipleRecnoDataBuilder" /> 12 <link rel="next" href="dbgetenv.html" title="Db::get_env()" /> 13 </head> 14 <body> 15 <div class="navheader"> 16 <table width="100%" summary="Navigation header"> 17 <tr> 18 <th colspan="3" align="center">Chapter��5.�� 19 The DbEnv Handle 20 </th> 21 </tr> 22 <tr> 23 <td width="20%" align="left"><a accesskey="p" href="dbmultiplerecnodatabuilder.html">Prev</a>��</td> 24 <th width="60%" align="center">��</th> 25 <td width="20%" align="right">��<a accesskey="n" href="dbgetenv.html">Next</a></td> 26 </tr> 27 </table> 28 <hr /> 29 </div> 30 <div class="chapter" lang="en" xml:lang="en"> 31 <div class="titlepage"> 32 <div> 33 <div> 34 <h2 class="title"><a id="env"></a>Chapter��5.�� 35 The DbEnv Handle 36 </h2> 37 </div> 38 </div> 39 </div> 40 <p> 41 The <code class="classname">DbEnv</code> object is the handle for a Berkeley DB environment 42 ��� a collection including support for some or all of caching, locking, logging and 43 transaction subsystems, as well as databases and log files. Methods of the 44 <code class="classname">DbEnv</code> handle are used to configure the environment as well as 45 to operate on subsystems and databases in the environment. 46 </p> 47 <p> 48 <code class="classname">DbEnv</code> handles 49 50 are opened using the <a class="xref" href="envopen.html" title="DbEnv::open()">DbEnv::open()</a> 51 method. 52 </p> 53 <p> 54 When you are done using your environment, close it using the 55 <a class="xref" href="envclose.html" title="DbEnv::close()">DbEnv::close()</a> method. Before closing your 56 environment, make sure all open database handles are closed first. See the 57 <a class="xref" href="dbclose.html" title="Db::close()">Db::close()</a> method for more information. 58 </p> 59 <div class="sect1" lang="en" xml:lang="en"> 60 <div class="titlepage"> 61 <div> 62 <div> 63 <h2 class="title" style="clear: both"><a id="envlist"></a>Database Environments and Related Methods</h2> 64 </div> 65 </div> 66 </div> 67 <div class="navtable"> 68 <table border="1" width="80%"> 69 <thead> 70 <tr> 71 <th>Database Environment Operations</th> 72 <th>Description</th> 73 </tr> 74 </thead> 75 <tbody> 76 <tr> 77 <td> 78 <a class="xref" href="dbgetenv.html" title="Db::get_env()">Db::get_env()</a> 79 </td> 80 <td>Return the Db's underlying DbEnv handle </td> 81 </tr> 82 <tr> 83 <td> 84 <a class="xref" href="envclose.html" title="DbEnv::close()">DbEnv::close()</a> 85 </td> 86 <td>Close an environment</td> 87 </tr> 88 <tr> 89 <td> 90 <a class="xref" href="envcreate.html" title="DbEnv">DbEnv</a> 91 </td> 92 <td>Create an environment handle</td> 93 </tr> 94 <tr> 95 <td> 96 <a class="xref" href="envdbremove.html" title="DbEnv::dbremove()">DbEnv::dbremove()</a> 97 </td> 98 <td>Remove a database</td> 99 </tr> 100 <tr> 101 <td> 102 <a class="xref" href="envdbrename.html" title="DbEnv::dbrename()">DbEnv::dbrename()</a> 103 </td> 104 <td>Rename a database</td> 105 </tr> 106 <tr> 107 <td> 108 <a class="xref" href="enverr.html" title="DbEnv::err()">DbEnv::err()</a> 109 </td> 110 <td>Error message</td> 111 </tr> 112 <tr> 113 <td> 114 <a class="xref" href="envfailchk.html" title="DbEnv::failchk()">DbEnv::failchk()</a> 115 </td> 116 <td>Check for thread failure</td> 117 </tr> 118 <tr> 119 <td> 120 <a class="xref" href="envfileid_reset.html" title="DbEnv::fileid_reset()">DbEnv::fileid_reset()</a> 121 </td> 122 <td>Reset database file IDs</td> 123 </tr> 124 <tr> 125 <td> 126 <a class="xref" href="envget_home.html" title="DbEnv::get_home()">DbEnv::get_home()</a> 127 </td> 128 <td>Return environment's home directory</td> 129 </tr> 130 <tr> 131 <td> 132 <a class="xref" href="envget_open_flags.html" title="DbEnv::get_open_flags()">DbEnv::get_open_flags()</a> 133 </td> 134 <td>Return flags with which the environment was opened</td> 135 </tr> 136 <tr> 137 <td> 138 <a class="xref" href="envlsn_reset.html" title="DbEnv::lsn_reset()">DbEnv::lsn_reset()</a> 139 </td> 140 <td>Reset database file LSNs</td> 141 </tr> 142 <tr> 143 <td> 144 <a class="xref" href="envopen.html" title="DbEnv::open()">DbEnv::open()</a> 145 </td> 146 <td>Open an environment</td> 147 </tr> 148 <tr> 149 <td> 150 <a class="xref" href="envremove.html" title="DbEnv::remove()">DbEnv::remove()</a> 151 </td> 152 <td>Remove an environment</td> 153 </tr> 154 <tr> 155 <td> 156 <a class="xref" href="envstat.html" title="DbEnv::stat_print()">DbEnv::stat_print()</a> 157 </td> 158 <td>Environment statistics</td> 159 </tr> 160 <tr> 161 <td> 162 <a class="xref" href="envstrerror.html" title="DbEnv::strerror()">DbEnv::strerror()</a> 163 </td> 164 <td>Error strings</td> 165 </tr> 166 <tr> 167 <td> 168 <a class="xref" href="envversion.html" title="DbEnv::version()">DbEnv::version()</a> 169 </td> 170 <td>Return version information</td> 171 </tr> 172 <tr> 173 <td colspan="2"> 174 <span class="bold"> 175 <strong>Environment Configuration</strong> 176 </span> 177 </td> 178 </tr> 179 <tr> 180 <td> 181 <a class="xref" href="envadd_data_dir.html" title="DbEnv::add_data_dir()">DbEnv::add_data_dir()</a> 182 </td> 183 <td>add an environment data directory</td> 184 </tr> 185 <tr> 186 <td> 187 <a class="xref" href="envset_alloc.html" title="DbEnv::set_alloc()">DbEnv::set_alloc()</a> 188 </td> 189 <td>Set local space allocation functions</td> 190 </tr> 191 <tr> 192 <td> 193 <a class="xref" href="envset_app_dispatch.html" title="DbEnv::set_app_dispatch()">DbEnv::set_app_dispatch()</a> 194 </td> 195 <td>Configure application recovery callback</td> 196 </tr> 197 <tr> 198 <td><a class="xref" href="envset_data_dir.html" title="DbEnv::set_data_dir()">DbEnv::set_data_dir()</a>, <a class="xref" href="envget_data_dirs.html" title="DbEnv::get_data_dirs()">DbEnv::get_data_dirs()</a></td> 199 <td>Set/get the environment data directory</td> 200 </tr> 201 <tr> 202 <td><a class="xref" href="envset_create_dir.html" title="DbEnv::set_create_dir()">DbEnv::set_create_dir()</a>, <a class="xref" href="envget_create_dir.html" title="DbEnv::get_create_dir()">DbEnv::get_create_dir()</a></td> 203 <td>add an environment data directory</td> 204 </tr> 205 <tr> 206 <td><a class="xref" href="envset_encrypt.html" title="DbEnv::set_encrypt()">DbEnv::set_encrypt()</a>, <a class="xref" href="envget_encrypt_flags.html" title="DbEnv::get_encrypt_flags()">DbEnv::get_encrypt_flags()</a></td> 207 <td>Set/get the environment cryptographic key</td> 208 </tr> 209 <tr> 210 <td> 211 <a class="xref" href="envevent_notify.html" title="DbEnv::set_event_notify()">DbEnv::set_event_notify()</a> 212 </td> 213 <td>Set event notification callback</td> 214 </tr> 215 <tr> 216 <td> 217 <a class="xref" href="envset_errcall.html" title="DbEnv::set_errcall()">DbEnv::set_errcall()</a> 218 </td> 219 <td>Set error message callbacks</td> 220 </tr> 221 <tr> 222 <td><a class="xref" href="envset_errfile.html" title="DbEnv::set_errfile()">DbEnv::set_errfile()</a>, <a class="xref" href="envget_errfile.html" title="DbEnv::get_errfile()">DbEnv::get_errfile()</a></td> 223 <td>Set/get error message FILE</td> 224 </tr> 225 <tr> 226 <td> 227 <a class="xref" href="envset_error_stream.html" title="DbEnv::set_error_stream()">DbEnv::set_error_stream()</a> 228 </td> 229 <td>Set C++ ostream used for error messages</td> 230 </tr> 231 <tr> 232 <td><a class="xref" href="envset_errpfx.html" title="DbEnv::set_errpfx()">DbEnv::set_errpfx()</a>, <a class="xref" href="envget_errpfx.html" title="DbEnv::get_errpfx()">DbEnv::get_errpfx()</a></td> 233 <td>Set/get error message prefix</td> 234 </tr> 235 <tr> 236 <td> 237 <a class="xref" href="envset_feedback.html" title="DbEnv::set_feedback()">DbEnv::set_feedback()</a> 238 </td> 239 <td>Set feedback callback</td> 240 </tr> 241 <tr> 242 <td><a class="xref" href="envset_flags.html" title="DbEnv::set_flags()">DbEnv::set_flags()</a>, <a class="xref" href="envget_flags.html" title="DbEnv::get_flags()">DbEnv::get_flags()</a></td> 243 <td>Environment configuration</td> 244 </tr> 245 <tr> 246 <td><a class="xref" href="envset_intermediate_dir_mode.html" title="DbEnv::set_intermediate_dir_mode()">DbEnv::set_intermediate_dir_mode()</a>, <a class="xref" href="envget_intermediate_dir_mode.html" title="DbEnv::get_intermediate_dir_mode()">DbEnv::get_intermediate_dir_mode()</a></td> 247 <td>Set/get intermediate directory creation mode</td> 248 </tr> 249 <tr> 250 <td> 251 <a class="xref" href="envset_isalive.html" title="DbEnv::set_isalive()">DbEnv::set_isalive()</a> 252 </td> 253 <td>Set thread is-alive callback</td> 254 </tr> 255 <tr> 256 <td> 257 <a class="xref" href="envset_message_stream.html" title="DbEnv::set_message_stream()">DbEnv::set_message_stream()</a> 258 </td> 259 <td>Set C++ ostream used for informational messages</td> 260 </tr> 261 <tr> 262 <td> 263 <a class="xref" href="envset_msgcall.html" title="DbEnv::set_msgcall()">DbEnv::set_msgcall()</a> 264 </td> 265 <td>Set informational message callback</td> 266 </tr> 267 <tr> 268 <td><a class="xref" href="envset_msgfile.html" title="DbEnv::set_msgfile()">DbEnv::set_msgfile()</a>, <a class="xref" href="envget_msgfile.html" title="DbEnv::get_msgfile()">DbEnv::get_msgfile()</a></td> 269 <td>Set/get informational message FILE</td> 270 </tr> 271 <tr> 272 <td><a class="xref" href="envset_shm_key.html" title="DbEnv::set_shm_key()">DbEnv::set_shm_key()</a>, <a class="xref" href="envget_shm_key.html" title="DbEnv::get_shm_key()">DbEnv::get_shm_key()</a></td> 273 <td>Set/get system memory shared segment ID</td> 274 </tr> 275 <tr> 276 <td><a class="xref" href="envset_thread_count.html" title="DbEnv::set_thread_count()">DbEnv::set_thread_count()</a>, <a class="xref" href="envget_thread_count.html" title="DbEnv::get_thread_count()">DbEnv::get_thread_count()</a></td> 277 <td>Set/get approximate thread count</td> 278 </tr> 279 <tr> 280 <td> 281 <a class="xref" href="envset_thread_id.html" title="DbEnv::set_thread_id()">DbEnv::set_thread_id()</a> 282 </td> 283 <td>Set thread of control ID function</td> 284 </tr> 285 <tr> 286 <td> 287 <a class="xref" href="envset_thread_id_string.html" title="DbEnv::set_thread_id_string()">DbEnv::set_thread_id_string()</a> 288 </td> 289 <td>Set thread of control ID format function</td> 290 </tr> 291 <tr> 292 <td><a class="xref" href="envset_timeout.html" title="DbEnv::set_timeout()">DbEnv::set_timeout()</a>, <a class="xref" href="envget_timeout.html" title="DbEnv::get_timeout()">DbEnv::get_timeout()</a></td> 293 <td>Set/get lock and transaction timeout</td> 294 </tr> 295 <tr> 296 <td><a class="xref" href="envset_tmp_dir.html" title="DbEnv::set_tmp_dir()">DbEnv::set_tmp_dir()</a>, <a class="xref" href="envget_tmp_dir.html" title="DbEnv::get_tmp_dir()">DbEnv::get_tmp_dir()</a></td> 297 <td>Set/get the environment temporary file directory</td> 298 </tr> 299 <tr> 300 <td><a class="xref" href="envset_verbose.html" title="DbEnv::set_verbose()">DbEnv::set_verbose()</a>, <a class="xref" href="envget_verbose.html" title="DbEnv::get_verbose()">DbEnv::get_verbose()</a></td> 301 <td>Set/get verbose messages</td> 302 </tr> 303 <tr> 304 <td><a class="xref" href="envset_cachesize.html" title="DbEnv::set_cachesize()">DbEnv::set_cachesize()</a>, <a class="xref" href="envget_cachesize.html" title="DbEnv::get_cachesize()">DbEnv::get_cachesize()</a></td> 305 <td>Set/get the environment cache size</td> 306 </tr> 307 </tbody> 308 </table> 309 </div> 310 </div> 311 </div> 312 <div class="navfooter"> 313 <hr /> 314 <table width="100%" summary="Navigation footer"> 315 <tr> 316 <td width="40%" align="left"><a accesskey="p" href="dbmultiplerecnodatabuilder.html">Prev</a>��</td> 317 <td width="20%" align="center">��</td> 318 <td 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