mirror of
https://github.com/sigmasternchen/php-doc-en
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1634a88641
git-svn-id: https://svn.php.net/repository/phpdoc/en/trunk@330340 c90b9560-bf6c-de11-be94-00142212c4b1
76 lines
1.9 KiB
XML
76 lines
1.9 KiB
XML
<?xml version="1.0" encoding="utf-8"?>
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<!-- $Revision$ -->
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<book xml:id="book.chdb" xmlns="http://docbook.org/ns/docbook" xmlns:xlink="http://www.w3.org/1999/xlink">
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<title>Constant hash database</title>
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<titleabbrev>chdb</titleabbrev>
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<preface xml:id="intro.chdb">
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&reftitle.intro;
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<para>
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CHDB (constant hash database) is a fast key-value database for constant data,
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realized by using a memory-mapped file and thus providing the following
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functionalities:
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<itemizedlist spacing="compact">
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<listitem>
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<para>
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Extremely fast initial load, regardless of the size of the database.
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</para>
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</listitem>
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<listitem>
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<para>
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Only the pages of the file which are actually used are loaded from the
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disk.
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</para>
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</listitem>
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<listitem>
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<para>
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Once a page is loaded it is shared across multiple processes.
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</para>
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</listitem>
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<listitem>
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<para>
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Loaded pages are cached across multiple requests and even process recycling.
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</para>
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</listitem>
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</itemizedlist>
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</para>
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<para>
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A typical use of CHDB is as a faster alternative to defining many PHP
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constants.
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</para>
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<para>
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CHDB is internally implemented as a hash-table using a
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<link xlink:href="&url.perfecthashing;">perfect hashing</link>
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function, thus guaranteeing worst case O(1) lookup time.
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</para>
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</preface>
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&reference.chdb.setup;
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&reference.chdb.constants;
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&reference.chdb.examples;
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&reference.chdb.chdb;
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&reference.chdb.reference;
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</book>
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<!-- Keep this comment at the end of the file
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Local variables:
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mode: sgml
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sgml-omittag:t
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sgml-shorttag:t
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sgml-minimize-attributes:nil
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sgml-always-quote-attributes:t
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sgml-indent-step:1
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sgml-indent-data:t
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indent-tabs-mode:nil
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sgml-parent-document:nil
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sgml-default-dtd-file:"~/.phpdoc/manual.ced"
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sgml-exposed-tags:nil
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sgml-local-catalogs:nil
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sgml-local-ecat-files:nil
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End:
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vim600: syn=xml fen fdm=syntax fdl=2 si
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vim: et tw=78 syn=sgml
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vi: ts=1 sw=1
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-->
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