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
|
<?xml version="1.0" encoding="utf-8"?>
<!-- $Revision: 330340 $ -->
<book xml:id="book.chdb" xmlns="http://docbook.org/ns/docbook" xmlns:xlink="http://www.w3.org/1999/xlink">
<title>Constant hash database</title>
<titleabbrev>chdb</titleabbrev>
<preface xml:id="intro.chdb">
&reftitle.intro;
<para>
CHDB (constant hash database) is a fast key-value database for constant data,
realized by using a memory-mapped file and thus providing the following
functionalities:
<itemizedlist spacing="compact">
<listitem>
<para>
Extremely fast initial load, regardless of the size of the database.
</para>
</listitem>
<listitem>
<para>
Only the pages of the file which are actually used are loaded from the
disk.
</para>
</listitem>
<listitem>
<para>
Once a page is loaded it is shared across multiple processes.
</para>
</listitem>
<listitem>
<para>
Loaded pages are cached across multiple requests and even process recycling.
</para>
</listitem>
</itemizedlist>
</para>
<para>
A typical use of CHDB is as a faster alternative to defining many PHP
constants.
</para>
<para>
CHDB is internally implemented as a hash-table using a
<link xlink:href="&url.perfecthashing;">perfect hashing</link>
function, thus guaranteeing worst case O(1) lookup time.
</para>
</preface>
&reference.chdb.setup;
&reference.chdb.constants;
&reference.chdb.examples;
&reference.chdb.chdb;
&reference.chdb.reference;
</book>
<!-- Keep this comment at the end of the file
Local variables:
mode: sgml
sgml-omittag:t
sgml-shorttag:t
sgml-minimize-attributes:nil
sgml-always-quote-attributes:t
sgml-indent-step:1
sgml-indent-data:t
indent-tabs-mode:nil
sgml-parent-document:nil
sgml-default-dtd-file:"~/.phpdoc/manual.ced"
sgml-exposed-tags:nil
sgml-local-catalogs:nil
sgml-local-ecat-files:nil
End:
vim600: syn=xml fen fdm=syntax fdl=2 si
vim: et tw=78 syn=sgml
vi: ts=1 sw=1
-->
|
