1<!--$Id: upgrade.so,v 10.17 2001/03/10 19:05:22 bostic Exp $--> 2<!--Copyright (c) 1997,2008 Oracle. All rights reserved.--> 3<!--See the file LICENSE for redistribution information.--> 4<html> 5<head> 6<title>Berkeley DB Reference Guide: Database upgrade</title> 7<meta name="description" content="Berkeley DB: An embedded database programmatic toolkit."> 8<meta name="keywords" content="embedded,database,programmatic,toolkit,btree,hash,hashing,transaction,transactions,locking,logging,access method,access methods,Java,C,C++"> 9</head> 10<body bgcolor=white> 11<a name="2"><!--meow--></a> 12<table width="100%"><tr valign=top> 13<td><b><dl><dt>Berkeley DB Reference Guide:<dd>Access Methods</dl></b></td> 14<td align=right><a href="/am/truncate.html"><img src="/images/prev.gif" alt="Prev"></a><a href="/toc.html"><img src="/images/ref.gif" alt="Ref"></a><a href="/am/verify.html"><img src="/images/next.gif" alt="Next"></a> 15</td></tr></table> 16<p align=center><b>Database upgrade</b></p> 17<p>When upgrading to a new release of Berkeley DB, it may be necessary to upgrade 18the on-disk format of already-created database files. <b>Berkeley DB 19database upgrades are done in place, and so are potentially 20destructive.</b> This means that if the system crashes during the upgrade 21procedure, or if the upgrade procedure runs out of disk space, the 22databases may be left in an inconsistent and unrecoverable state. To 23guard against failure, the procedures outlined in 24<a href="/ref/upgrade/process.html">Upgrading Berkeley DB installations</a> 25should be carefully followed. If you are not performing catastrophic 26archival as part of your application upgrade process, you should at 27least copy your database to archival media, verify that your archival 28media is error-free and readable, and that copies of your backups are 29stored offsite!</p> 30<p>The actual database upgrade is done using the <a href="/api_c/db_upgrade.html">DB->upgrade</a> 31method, or by dumping the database using the old version of the Berkeley DB 32software and reloading it using the current version.</p> 33<p>After an upgrade, Berkeley DB applications must be recompiled to use the new 34Berkeley DB library before they can access an upgraded database. 35<b>There is no guarantee that applications compiled against 36previous releases of Berkeley DB will work correctly with an upgraded database 37format. Nor is there any guarantee that applications compiled against 38newer releases of Berkeley DB will work correctly with the previous database 39format.</b> We do guarantee that any archived database may be upgraded 40using a current Berkeley DB software release and the <a href="/api_c/db_upgrade.html">DB->upgrade</a> 41method, and there is no need to step-wise upgrade the database using 42intermediate releases of Berkeley DB. Sites should consider archiving 43appropriate copies of their application or application sources if they 44may need to access archived databases without first upgrading them.</p> 45<table width="100%"><tr><td><br></td><td align=right><a href="/am/truncate.html"><img src="/images/prev.gif" alt="Prev"></a><a href="/toc.html"><img src="/images/ref.gif" alt="Ref"></a><a href="/am/verify.html"><img src="/images/next.gif" alt="Next"></a> 46</td></tr></table> 47<p><font size=1>Copyright (c) 1996,2008 Oracle. All rights reserved.</font> 48</body> 49</html> 50
