Gecko [ 122.154.134.11 ]

Name	Size	Permission
close.html	2.46 KB	-rw-r--r--
cxx.html	2 KB	-rw-r--r--
db.html	2.99 KB	-rw-r--r--
db_cxx.html	3.08 KB	-rw-r--r--
dbenv.html	4.91 KB	-rw-r--r--
dbenv_cxx.html	3.47 KB	-rw-r--r--
dbinfo.html	5.05 KB	-rw-r--r--
disk.html	2 KB	-rw-r--r--
eacces.html	1.83 KB	-rw-r--r--
eagain.html	2.22 KB	-rw-r--r--
envopen.html	8.38 KB	-rw-r--r--
func.html	3.42 KB	-rw-r--r--
intro.html	1.63 KB	-rw-r--r--
java.html	2.21 KB	-rw-r--r--
join.html	1.91 KB	-rw-r--r--
jump_set.html	3.75 KB	-rw-r--r--
lock_detect.html	1.63 KB	-rw-r--r--
lock_notheld.html	1.79 KB	-rw-r--r--
lock_put.html	1.67 KB	-rw-r--r--
lock_stat.html	1.6 KB	-rw-r--r--
log_register.html	1.63 KB	-rw-r--r--
log_stat.html	1.53 KB	-rw-r--r--
memp_stat.html	1.67 KB	-rw-r--r--
open.html	3.68 KB	-rw-r--r--
rmw.html	2.17 KB	-rw-r--r--
stat.html	1.58 KB	-rw-r--r--
toc.html	2.96 KB	-rw-r--r--
txn_begin.html	1.62 KB	-rw-r--r--
txn_commit.html	1.62 KB	-rw-r--r--
txn_stat.html	1.52 KB	-rw-r--r--
value_set.html	2.9 KB	-rw-r--r--
xa.html	2.39 KB	-rw-r--r--

Code Editor : open.html

<html>
<head>
<title>Berkeley DB Reference Guide: Release 3.0: database open/close</title>
<meta name="description" content="Berkeley DB: An embedded database programmatic toolkit.">
<meta name="keywords" content="embedded,database,programmatic,toolkit,btree,hash,hashing,transaction,transactions,locking,logging,access method,access methods,Java,C,C++">
</head>
<body bgcolor=white>
<table width="100%"><tr valign=top>
<td><dl><dt>Berkeley DB Reference Guide:<dd>Upgrading Berkeley DB Applications</dl></td>
<td align=right><a href="../upgrade.3.0/dbenv.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/xa.html"><img src="../../images/next.gif" alt="Next"></a>
</td></tr></table>
Release 3.0: database open/close
Database opens were changed in the Berkeley DB 3.0 release in a similar way to
environment opens.
To upgrade your application, first find each place your application opens
a database, that is, calls the db_open function. Each of these calls
should be replaced with calls to <a href="../../api_c/db_class.html">db_create</a> and <a href="../../api_c/db_open.html">DB-&gt;open</a>.
Here's an example creating a Berkeley DB database using the 2.X interface:
<blockquote><pre>DB *dbp;
DB_ENV *dbenv;
int ret;

if ((ret = db_open(DATABASE,
 DB_BTREE, DB_CREATE, 0664, dbenv, NULL, &dbp)) != 0)
	return (ret);</pre></blockquote>
In the Berkeley DB 3.0 release, this code would be written as:
<blockquote><pre>DB *dbp;
DB_ENV *dbenv;
int ret;

if ((ret = db_create(&dbp, dbenv, 0)) != 0)
	return (ret);

if ((ret = dbp-&gt;open(dbp,
 DATABASE, NULL, DB_BTREE, DB_CREATE, 0664)) != 0) {
	(void)dbp-&gt;close(dbp, 0);
	return (ret);
}</pre></blockquote>
As you can see, the arguments to db_open and to <a href="../../api_c/db_open.html">DB-&gt;open</a> are
largely the same. There is some re-organization, and note that the
enclosing <a href="../../api_c/env_class.html">DB_ENV</a> structure is specified when the <a href="../../api_c/db_class.html">DB</a> object
is created using the <a href="../../api_c/db_class.html">db_create</a> function. There is one
additional argument to <a href="../../api_c/db_open.html">DB-&gt;open</a>, argument #3. For backward
compatibility with the 2.X Berkeley DB releases, simply set that argument to
NULL.
There are two additional issues with the db_open call.
First, it was possible in the 2.X releases for an application to provide
an environment that did not contain a shared memory buffer pool as the
database environment, and Berkeley DB would create a private one automatically.
This functionality is no longer available, applications must specify the
<a href="../../api_c/env_open.html#DB_INIT_MPOOL">DB_INIT_MPOOL</a> flag if databases are going to be opened in the
environment.
The final issue with upgrading the db_open call is that the DB_INFO
structure is no longer used, having been replaced by individual methods
on the <a href="../../api_c/db_class.html">DB</a> handle. That change is discussed in detail later in
this chapter.
<table width="100%"><tr><td> </td><td align=right><a href="../upgrade.3.0/dbenv.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/xa.html"><img src="../../images/next.gif" alt="Next"></a>
</td></tr></table>
Copyright (c) 1996,2008 Oracle. All rights reserved.
</body>
</html>

${this.title}

Code Editor : open.html