1<!--$Id: format.so,v 10.16 2001/03/13 20:39:47 bostic Exp $--> 2<!--Copyright (c) 1997,2008 Oracle. All rights reserved.--> 3<!--See the file LICENSE for redistribution information.--> 4<html> 5<head> 6<title>Berkeley DB Reference Guide: Dump output formats</title> 7<meta name="description" content="Berkeley DB: An embedded database programmatic toolkit."> 8<meta name="keywords" content="embedded,database,programmatic,toolkit,btree,hash,hashing,transaction,transactions,locking,logging,access method,access methods,Java,C,C++"> 9</head> 10<body bgcolor=white> 11<table width="100%"><tr valign=top> 12<td><b><dl><dt>Berkeley DB Reference Guide:<dd>Dumping and Reloading</dl></b></td> 13<td align=right><a href="../dumpload/utility.html"><img src="../../images/prev.gif" alt="Prev"></a><a href="../toc.html"><img src="../../images/ref.gif" alt="Ref"></a><a href="../dumpload/text.html"><img src="../../images/next.gif" alt="Next"></a> 14</td></tr></table> 15<p align=center><b>Dump output formats</b></p> 16<p>There are two output formats used by <a href="../../utility/db_dump.html">db_dump</a> and <a href="../../utility/db_dump.html">db_dump185</a>.</p> 17<p>In both output formats, the first few lines of the output contain header 18information describing the underlying access method, filesystem page size, 19and other bookkeeping information.</p> 20<p>The header information starts with a single line, VERSION=N, where N is 21the version number of the dump output format.</p> 22<p>The header information is then output in name=value pairs, where name may 23be any of the keywords listed in the <a href="../../utility/db_load.html">db_load</a> manual page, and 24value will be its value. Although this header information can be manually 25edited before the database is reloaded, there is rarely any reason to do 26so because all of this information can also be specified or overridden by 27command-line arguments to <a href="../../utility/db_load.html">db_load</a>.</p> 28<p>The header information ends with single line HEADER=END.</p> 29<p>Following the header information are the key/data pairs from the 30database. If the database being dumped is a Btree or Hash database, or 31if the <b>-k</b> option was specified, the output will be paired lines 32of text where the first line of the pair is the key item, and the second 33line of the pair is its corresponding data item. If the database being 34dumped is a Queue or Recno database, and the <b>-k</b> option was not 35specified, the output will be lines of text where each line is the next 36data item for the database. Each of these lines is preceded by a single 37space.</p> 38<p>If the <b>-p</b> option to <a href="../../utility/db_dump.html">db_dump</a> or <a href="../../utility/db_dump.html">db_dump185</a> was 39specified, the key/data lines will consist of single characters 40representing any characters from the database that are <i>printing 41characters</i> and backslash (<b>\</b>) escaped characters 42for any that were not. Backslash characters appearing in the output mean 43one of two things: if the backslash character precedes another backslash 44character, it means that a literal backslash character occurred in the 45key or data item. If the backslash character precedes any other 46character, the next two characters must be interpreted as hexadecimal 47specification of a single character; for example, <b>\0a</b> 48is a newline character in the ASCII character set.</p> 49<p>Although some care should be exercised, it is perfectly reasonable to use 50standard text editors and tools to edit databases dumped using the 51<b>-p</b> option before reloading them using the <a href="../../utility/db_load.html">db_load</a> 52utility.</p> 53<p>Note that the definition of a printing character may vary from system to 54system, so database representations created using the <b>-p</b> 55option may be less portable than those created without it.</p> 56<p>If the <b>-p</b> option to <a href="../../utility/db_dump.html">db_dump</a> or <a href="../../utility/db_dump.html">db_dump185</a> is 57not specified, each output line will consist of paired hexadecimal values; 58for example, the line <b>726f6f74</b> is the string <b>root</b> in 59the ASCII character set.</p> 60<p>In all output formats, the key and data items are ended by a single line 61DATA=END.</p> 62<p>Where multiple databases have been dumped from a file, the overall output 63will repeat; that is, a new set of headers and a new set of data items.</p> 64<table width="100%"><tr><td><br></td><td align=right><a href="../dumpload/utility.html"><img src="../../images/prev.gif" alt="Prev"></a><a href="../toc.html"><img src="../../images/ref.gif" alt="Ref"></a><a href="../dumpload/text.html"><img src="../../images/next.gif" alt="Next"></a> 65</td></tr></table> 66<p><font size=1>Copyright (c) 1996,2008 Oracle. All rights reserved.</font> 67</body> 68</html> 69
