1<!--$Id: dbenv.so,v 11.13 2006/04/24 17:26:34 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: Release 3.0: the DB_ENV structure</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<table width="100%"><tr valign=top> 12<td><b><dl><dt>Berkeley DB Reference Guide:<dd>Upgrading Berkeley DB Applications</dl></b></td> 13<td align=right><a href="../upgrade.3.0/func.html"><img src="../../images/prev.gif" alt="Prev"></a><a href="../toc.html"><img src="../../images/ref.gif" alt="Ref"></a><a href="../upgrade.3.0/open.html"><img src="../../images/next.gif" alt="Next"></a> 14</td></tr></table> 15<p align=center><b>Release 3.0: the DB_ENV structure</b></p> 16<p>The <a href="../../api_c/env_class.html">DB_ENV</a> structure is now opaque for applications in the Berkeley DB 173.0 release. Accesses to any fields within that structure by the 18application should be replaced with method calls. The following example 19illustrates this using the historic errpfx structure field. In the Berkeley DB 202.X releases, applications set error prefixes using code similar to the 21following:</p> 22<blockquote><pre>DB_ENV *dbenv; 23<p> 24 dbenv->errpfx = "my prefix";</pre></blockquote> 25<p>in the Berkeley DB 3.X releases, this should be done using the 26<a href="../../api_c/env_set_errpfx.html">DB_ENV->set_errpfx</a> method, as follows:</p> 27<blockquote><pre>DB_ENV *dbenv; 28<p> 29 dbenv->set_errpfx(dbenv, "my prefix");</pre></blockquote> 30<p>The following table lists the <a href="../../api_c/env_class.html">DB_ENV</a> fields previously used by 31applications and the methods that should now be used to set them.</p> 32<table border=1 align=center> 33<tr><th><a href="../../api_c/env_class.html">DB_ENV</a> field</th><th>Berkeley DB 3.X method</th></tr> 34<tr><td>db_errcall</td><td><a href="../../api_c/env_set_errcall.html">DB_ENV->set_errcall</a></td></tr> 35<tr><td>db_errfile</td><td><a href="../../api_c/env_set_errfile.html">DB_ENV->set_errfile</a></td></tr> 36<tr><td>db_errpfx</td><td><a href="../../api_c/env_set_errpfx.html">DB_ENV->set_errpfx</a></td></tr> 37<tr><td>db_lorder</td><td>This field was removed from the <a href="../../api_c/env_class.html">DB_ENV</a> structure in the Berkeley DB 383.0 release as no application should have ever used it. Any code using 39it should be evaluated for potential bugs.</td></tr> 40<tr><td>db_paniccall</td><td>DB_ENV->set_paniccall</td></tr> 41<tr><td>db_verbose</td><td><a href="../../api_c/env_set_verbose.html">DB_ENV->set_verbose</a> 42<p>Note: the db_verbose field was a simple boolean toggle, the 43<a href="../../api_c/env_set_verbose.html">DB_ENV->set_verbose</a> method takes arguments that specify exactly 44which verbose messages are desired.</p></td></tr> 45<tr><td>lg_max</td><td><a href="../../api_c/env_set_lg_max.html">DB_ENV->set_lg_max</a></td></tr> 46<tr><td>lk_conflicts</td><td><a href="../../api_c/env_set_lk_conflicts.html">DB_ENV->set_lk_conflicts</a></td></tr> 47<tr><td>lk_detect</td><td><a href="../../api_c/env_set_lk_detect.html">DB_ENV->set_lk_detect</a></td></tr> 48<tr><td>lk_max</td><td>dbenv->set_lk_max</td></tr> 49<tr><td>lk_modes</td><td><a href="../../api_c/env_set_lk_conflicts.html">DB_ENV->set_lk_conflicts</a></td></tr> 50<tr><td>mp_mmapsize</td><td><a href="../../api_c/env_set_mp_mmapsize.html">DB_ENV->set_mp_mmapsize</a></td></tr> 51<tr><td>mp_size</td><td><a href="../../api_c/env_set_cachesize.html">DB_ENV->set_cachesize</a> 52<p>Note: the <a href="../../api_c/env_set_cachesize.html">DB_ENV->set_cachesize</a> function takes additional arguments. 53Setting both the second argument (the number of GB in the pool) and the 54last argument (the number of memory pools to create) to 0 will result in 55behavior that is backward-compatible with previous Berkeley DB releases.</p></td></tr> 56<tr><td>tx_info</td><td>This field was used by applications as an argument to the transaction 57subsystem functions. As those functions take references to a 58<a href="../../api_c/env_class.html">DB_ENV</a> structure as arguments in the Berkeley DB 3.0 release, it should 59no longer be used by any application.</td></tr> 60<tr><td>tx_max</td><td><a href="../../api_c/env_set_tx_max.html">DB_ENV->set_tx_max</a></td></tr> 61<tr><td>tx_recover</td><td>dbenv->set_tx_recover</td></tr> 62</table> 63<table width="100%"><tr><td><br></td><td align=right><a href="../upgrade.3.0/func.html"><img src="../../images/prev.gif" alt="Prev"></a><a href="../toc.html"><img src="../../images/ref.gif" alt="Ref"></a><a href="../upgrade.3.0/open.html"><img src="../../images/next.gif" alt="Next"></a> 64</td></tr></table> 65<p><font size=1>Copyright (c) 1996,2008 Oracle. All rights reserved.</font> 66</body> 67</html> 68
