mirror of
https://github.com/yasuhirokimura/db18
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Yasuhiro KIMURA
149 lines
7.1 KiB
HTML
149 lines
7.1 KiB
HTML
<?xml version="1.0" encoding="UTF-8" standalone="no"?>
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<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
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<html xmlns="http://www.w3.org/1999/xhtml">
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<head>
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<meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
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<title>Dump output formats</title>
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<link rel="stylesheet" href="gettingStarted.css" type="text/css" />
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<meta name="generator" content="DocBook XSL Stylesheets V1.73.2" />
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<link rel="start" href="index.html" title="Berkeley DB Programmer's Reference Guide" />
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<link rel="up" href="dumpload.html" title="Chapter 24. Dumping and Reloading Databases" />
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<link rel="prev" href="dumpload.html" title="Chapter 24. Dumping and Reloading Databases" />
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<link rel="next" href="dumpload_text.html" title="Loading text into databases" />
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</head>
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<body>
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<div xmlns="" class="navheader">
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<div class="libver">
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<p>Library Version 18.1.40</p>
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</div>
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<table width="100%" summary="Navigation header">
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<tr>
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<th colspan="3" align="center">Dump output formats</th>
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</tr>
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<tr>
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<td width="20%" align="left"><a accesskey="p" href="dumpload.html">Prev</a> </td>
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<th width="60%" align="center">Chapter 24. Dumping and Reloading Databases
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</th>
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<td width="20%" align="right"> <a accesskey="n" href="dumpload_text.html">Next</a></td>
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</tr>
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</table>
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<hr />
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</div>
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<div class="sect1" lang="en" xml:lang="en">
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<div class="titlepage">
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<div>
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<div>
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<h2 class="title" style="clear: both"><a id="dumpload_format"></a>Dump output formats</h2>
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</div>
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</div>
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</div>
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<p>
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There are two output formats used by the <a href="../api_reference/C/db_dump.html" class="olink">db_dump</a> utility and
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<a href="../api_reference/C/db_dump.html" class="olink">db_dump185</a> utility.
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</p>
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<p>
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In both output formats, the first few lines of the output
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contain header information describing the underlying access
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method, filesystem page size, and other bookkeeping
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information.
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</p>
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<p>
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The header information starts with a single line, VERSION=N,
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where N is the version number of the dump output
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format.
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</p>
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<p>
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The header information is then output in name=value pairs,
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where name may be any of the keywords listed in the <a href="../api_reference/C/db_load.html" class="olink">db_load</a> utility
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manual page, and value will be its value. Although this header
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information can be manually edited before the database is
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reloaded, there is rarely any reason to do so because all of
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this information can also be specified or overridden by
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command-line arguments to the <a href="../api_reference/C/db_load.html" class="olink">db_load</a> utility.
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</p>
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<p>
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The header information ends with single line
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HEADER=END.
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</p>
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<p>
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Following the header information are the key/data pairs from
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the database. If the database being dumped is a Btree or Hash
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database, or if the <span class="bold"><strong>-k</strong></span> option
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was specified, the output will be paired lines of text where
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the first line of the pair is the key item, and the second
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line of the pair is its corresponding data item. If the
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database being dumped is a Queue or Recno database, and the
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<span class="bold"><strong>-k</strong></span> option was not
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specified, the output will be lines of text where each line is
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the next data item for the database. Each of these lines is
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preceded by a single space.
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</p>
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<p>
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If the <span class="bold"><strong>-p</strong></span> option was
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specified to the <a href="../api_reference/C/db_dump.html" class="olink">db_dump</a> utility or <a href="../api_reference/C/db_dump.html" class="olink">db_dump185</a> utility, the key/data lines
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will consist of single characters representing any characters
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from the database that are <span class="emphasis"><em>printing
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characters</em></span> and backslash (<span class="bold"><strong>\</strong></span>)
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escaped characters for any that were not.
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Backslash characters appearing in the output mean one of two
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things: if the backslash character precedes another backslash
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character, it means that a literal backslash character
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occurred in the key or data item. If the backslash character
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precedes any other character, the next two characters must be
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interpreted as hexadecimal specification of a single
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character; for example, <span class="bold"><strong>\0a</strong></span>
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is a newline character in the ASCII character set.
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</p>
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<p>
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Although some care should be exercised, it is perfectly
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reasonable to use standard text editors and tools to edit
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databases dumped using the <span class="bold"><strong>-p</strong></span>
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option before reloading them using the <a href="../api_reference/C/db_load.html" class="olink">db_load</a> utility.
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</p>
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<p>
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Note that the definition of a printing character may vary
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from system to system, so database representations created
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using the <span class="bold"><strong>-p</strong></span> option may be
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less portable than those created without it.
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</p>
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<p>
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If the <span class="bold"><strong>-p</strong></span> option in not
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specified to <a href="../api_reference/C/db_dump.html" class="olink">db_dump</a> utility or <a href="../api_reference/C/db_dump.html" class="olink">db_dump185</a> utility, each output line will
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consist of paired hexadecimal values; for example, the line
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<span class="bold"><strong>726f6f74</strong></span> is the string
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<span class="bold"><strong>root</strong></span> in the ASCII
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character set.
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</p>
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<p>
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In all output formats, the key and data items are ended by a
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single line DATA=END.
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</p>
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<p>
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Where multiple databases have been dumped from a file, the
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overall output will repeat; that is, a new set of headers and
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a new set of data items.
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</p>
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</div>
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<div class="navfooter">
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<hr />
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<table width="100%" summary="Navigation footer">
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||
<tr>
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<td width="40%" align="left"><a accesskey="p" href="dumpload.html">Prev</a> </td>
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<td width="20%" align="center">
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<a accesskey="u" href="dumpload.html">Up</a>
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</td>
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<td width="40%" align="right"> <a accesskey="n" href="dumpload_text.html">Next</a></td>
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</tr>
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<tr>
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<td width="40%" align="left" valign="top">Chapter 24. Dumping and Reloading Databases
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</td>
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<td width="20%" align="center">
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<a accesskey="h" href="index.html">Home</a>
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</td>
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<td width="40%" align="right" valign="top"> Loading text into databases</td>
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</tr>
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</table>
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</div>
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</body>
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</html>
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