1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
|
<?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>Appendix A. Using the BFILE Extension</title>
<link rel="stylesheet" href="gettingStarted.css" type="text/css" />
<meta name="generator" content="DocBook XSL Stylesheets V1.73.2" />
<link rel="start" href="index.html" title="Getting Started with the Oracle Berkeley DB SQL APIs" />
<link rel="up" href="index.html" title="Getting Started with the Oracle Berkeley DB SQL APIs" />
<link rel="prev" href="datamigration.html" title="Data Migration" />
<link rel="next" href="bfile-sql.html" title="BFILE SQL Objects and Functions" />
</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">Appendix A. Using the BFILE Extension</th>
</tr>
<tr>
<td width="20%" align="left"><a accesskey="p" href="datamigration.html">Prev</a> </td>
<th width="60%" align="center"> </th>
<td width="20%" align="right"> <a accesskey="n" href="bfile-sql.html">Next</a></td>
</tr>
</table>
<hr />
</div>
<div class="appendix" lang="en" xml:lang="en">
<div class="titlepage">
<div>
<div>
<h2 class="title"><a id="bfile-extension"></a>Appendix A. Using the BFILE Extension</h2>
</div>
</div>
</div>
<p>
The BFILE data type allows the BDB SQL interface to access binary files that
are stored in the file system outside of the database. The binary
file can be queried in exactly the same way as any other data type
stored in the database, but Berkeley DB is able to save space in the
database file by not embedding a large amount of binary data in it.
This also helps overall database performance.
</p>
<p>
Internally, a BFILE column or attribute stores a BFILE locater,
which serves as a pointer to the binary file. The locater maintains
the directory alias and the filename. You can change the path of
BFILE without affecting the base table by using the BFILENAME function.
BFILE is somewhat like the BLOB data type, but it does not participate in
transactions and it is not recoverable. Instead, the underlying
operating system is expected to provide file integrity and durability.
</p>
<p>
The remainder of this section describes the various objects and
functions that the BFILE extension makes available to you.
In addition, complete examples of using these extensions are
available with your Berkeley DB distribution. They are placed in the
following location:
</p>
<pre class="programlisting"><db-dist>/lang/sql/sqlite/ext/bfile/examples</pre>
<div class="sect1" lang="en" xml:lang="en">
<div class="titlepage">
<div>
<div>
<h2 class="title" style="clear: both"><a id="bfile-support"></a>Supported Platforms and Languages</h2>
</div>
</div>
</div>
<p>
The BFILE extension is currently only supported for *nix platforms.
</p>
<p>
The BFILE extension it is not available in your library by
default. Instead, you must enable the extension when you
compile Berkeley DB. See the <em class="citetitle">Berkeley DB Installation and Build Guide</em>
for information on how to enable this extension when you build
Berkeley DB. Once you have enabled the extension, applications will
also need to load the BFILE library file:
<code class="literal">libbfile_ext.so</code>.
</p>
<p>
By default, the BFILE extension provides support for additional SQL
statements. With some extra configuration at Berkeley DB compile
time, you can also obtain support for extensions to the SQLite
C/C++ interface. Both the SQL extensions and the extensions
to the SQLite C/C++ interface are described in the
following sections.
</p>
</div>
</div>
<div class="navfooter">
<hr />
<table width="100%" summary="Navigation footer">
<tr>
<td width="40%" align="left"><a accesskey="p" href="datamigration.html">Prev</a> </td>
<td width="20%" align="center"> </td>
<td width="40%" align="right"> <a accesskey="n" href="bfile-sql.html">Next</a></td>
</tr>
<tr>
<td width="40%" align="left" valign="top">Data Migration </td>
<td width="20%" align="center">
<a accesskey="h" href="index.html">Home</a>
</td>
<td width="40%" align="right" valign="top"> BFILE SQL Objects and Functions</td>
</tr>
</table>
</div>
</body>
</html>
|
