<?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::upgrade()</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="dbtruncate.html" title="Db::truncate()" /> <link rel="next" href="dbverify.html" title="Db::verify()" /> </head> <body> <div xmlns="" class="navheader"> <div class="libver"> <p>Library Version 11.2.5.3</p> </div> <table width="100%" summary="Navigation header"> <tr> <th colspan="3" align="center">Db::upgrade()</th> </tr> <tr> <td width="20%" align="left"><a accesskey="p" href="dbtruncate.html">Prev</a> </td> <th width="60%" align="center">Chapter 2. The Db Handle </th> <td width="20%" align="right"> <a accesskey="n" href="dbverify.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="dbupgrade"></a>Db::upgrade()</h2> </div> </div> </div> <pre class="programlisting">#include <db_cxx.h> int Db::upgrade(const char *file, u_int32_t flags);</pre> <p> The <code class="methodname">Db::upgrade()</code> method upgrades all of the databases included in the file <span class="bold"><strong>file</strong></span>, if necessary. If no upgrade is necessary, <code class="methodname">Db::upgrade()</code> always returns success. </p> <p> <span class="bold"><strong>Database upgrades are done in place and are destructive. For example, if pages need to be allocated and no disk space is available, the database may be left corrupted. Backups should be made before databases are upgraded. See <a href="../../programmer_reference/am_upgrade.html" class="olink">Upgrading databases</a> for more information.</strong></span> </p> <p> Unlike all other database operations, <code class="methodname">Db::upgrade()</code> may only be done on a system with the same byte-order as the database. </p> <p> The <code class="methodname">Db::upgrade()</code> <span> <span> method either returns a non-zero error value or throws an exception that encapsulates a non-zero error value on failure, and returns 0 on success. </span> </span> </p> <div class="sect2" lang="en" xml:lang="en"> <div class="titlepage"> <div> <div> <h3 class="title"><a id="idp6000704"></a>Parameters</h3> </div> </div> </div> <div class="sect3" lang="en" xml:lang="en"> <div class="titlepage"> <div> <div> <h4 class="title"><a id="idp6001352"></a>file</h4> </div> </div> </div> <p> The <span class="bold"><strong>file</strong></span> parameter is the physical file containing the databases to be upgraded. </p> </div> <div class="sect3" lang="en" xml:lang="en"> <div class="titlepage"> <div> <div> <h4 class="title"><a id="idp5978128"></a>flags</h4> </div> </div> </div> <p> The <span class="bold"><strong>flags</strong></span> parameter must be set to 0 or the following value: </p> <div class="itemizedlist"> <ul type="disc"> <li> <p><a id="upgrade_DB_DUPSORT"></a> <code class="literal">DB_DUPSORT</code> </p> <p> <span class="bold"><strong>This flag is only meaningful when upgrading databases from releases before the Berkeley DB 3.1 release.</strong></span> </p> <p> As part of the upgrade from the Berkeley DB 3.0 release to the 3.1 release, the on-disk format of duplicate data items changed. To correctly upgrade the format requires applications to specify whether duplicate data items in the database are sorted or not. Specifying the DB_DUPSORT flag informs <code class="methodname">Db::upgrade()</code> that the duplicates are sorted; otherwise they are assumed to be unsorted. Incorrectly specifying the value of this flag may lead to database corruption. </p> <p> Further, because the <code class="methodname">Db::upgrade()</code> method upgrades a physical file (including all the databases it contains), it is not possible to use <code class="methodname">Db::upgrade()</code> to upgrade files in which some of the databases it includes have sorted duplicate data items, and some of the databases it includes have unsorted duplicate data items. If the file does not have more than a single database, if the databases do not support duplicate data items, or if all of the databases that support duplicate data items support the same style of duplicates (either sorted or unsorted), <code class="methodname">Db::upgrade()</code> will work correctly as long as the DB_DUPSORT flag is correctly specified. Otherwise, the file cannot be upgraded using <code class="methodname">Db::upgrade;()</code> it must be upgraded manually by dumping and reloading the databases. </p> </li> </ul> </div> </div> </div> <div class="sect2" lang="en" xml:lang="en"> <div class="titlepage"> <div> <div> <h3 class="title"><a id="idp6019936"></a>Environment Variables</h3> </div> </div> </div> <p> If the database was opened within a database environment, the environment variable <code class="literal">DB_HOME</code> may be used as the path of the database environment home. </p> <p> <code class="methodname">Db::upgrade()</code> is affected by any database directory specified using the <a class="xref" href="envset_data_dir.html" title="DbEnv::set_data_dir()">DbEnv::set_data_dir()</a> method, or by setting the "set_data_dir" string in the environment's <a href="../../programmer_reference/env_db_config.html#env_db_config.DB_CONFIG" class="olink">DB_CONFIG</a> file. </p> </div> <div class="sect2" lang="en" xml:lang="en"> <div class="titlepage"> <div> <div> <h3 class="title"><a id="idp6020792"></a>Errors</h3> </div> </div> </div> <p> The <code class="methodname">Db::upgrade()</code> <span> <span> method may fail and throw a <a class="link" href="dbexception.html" title="Chapter 6. The DbException Class">DbException</a> exception, encapsulating one of the following non-zero errors, or return one of the following non-zero errors: </span> </span> </p> <div class="sect3" lang="en" xml:lang="en"> <div class="titlepage"> <div> <div> <h4 class="title"><a id="idp6028776"></a>DB_OLD_VERSION</h4> </div> </div> </div> <p> The database cannot be upgraded by this version of the Berkeley DB software. </p> </div> </div> <div class="sect2" lang="en" xml:lang="en"> <div class="titlepage"> <div> <div> <h3 class="title"><a id="idp6027696"></a>Class</h3> </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> <h3 class="title"><a id="idp6024424"></a>See Also</h3> </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="dbtruncate.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="dbverify.html">Next</a></td> </tr> <tr> <td width="40%" align="left" valign="top">Db::truncate() </td> <td width="20%" align="center"> <a accesskey="h" href="index.html">Home</a> </td> <td width="40%" align="right" valign="top"> Db::verify()</td> </tr> </table> </div> </body> </html>