1<?xml version="1.0" encoding="UTF-8" standalone="no"?> 2<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> 3<html xmlns="http://www.w3.org/1999/xhtml"> 4 <head> 5 <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /> 6 <title>Database Limits and Portability</title> 7 <link rel="stylesheet" href="gettingStarted.css" type="text/css" /> 8 <meta name="generator" content="DocBook XSL Stylesheets V1.62.4" /> 9 <link rel="home" href="index.html" title="Getting Started with Berkeley DB" /> 10 <link rel="up" href="introduction.html" title="Chapter 1. Introduction to Berkeley DB " /> 11 <link rel="previous" href="accessmethods.html" title="Access Methods" /> 12 <link rel="next" href="environments.html" title="Environments" /> 13 </head> 14 <body> 15 <div class="navheader"> 16 <table width="100%" summary="Navigation header"> 17 <tr> 18 <th colspan="3" align="center">Database Limits and Portability</th> 19 </tr> 20 <tr> 21 <td width="20%" align="left"><a accesskey="p" href="accessmethods.html">Prev</a> </td> 22 <th width="60%" align="center">Chapter 1. Introduction to Berkeley DB </th> 23 <td width="20%" align="right"> <a accesskey="n" href="environments.html">Next</a></td> 24 </tr> 25 </table> 26 <hr /> 27 </div> 28 <div class="sect1" lang="en" xml:lang="en"> 29 <div class="titlepage"> 30 <div> 31 <div> 32 <h2 class="title" style="clear: both"><a id="databaseLimits"></a>Database Limits and Portability</h2> 33 </div> 34 </div> 35 <div></div> 36 </div> 37 <p> 38 Berkeley DB provides support for managing everything from very small 39 databases that fit entirely in memory, to extremely large databases 40 holding millions of records and terabytes of data. DB databases can 41 store up to 256 terabytes of data. Individual record keys or record 42 data can store up to 4 gigabytes of data. 43 </p> 44 <p> 45 DB's databases store data in a binary format that is portable across 46 platforms, even of differing endian-ness. Be aware, however, that 47 portability aside, some performance issues can crop up in the event that 48 you are using little endian architecture. See <a href="btree.html#comparators">Setting Comparison Functions</a> 49 for more information. 50 </p> 51 <p> 52 Also, DB's databases and data structures are designed for concurrent 53 access — they are thread-safe, and they share well across multiple 54 processes. That said, in order to allow multiple processes to share 55 databases and the cache, DB makes use of mechanisms that do not work 56 well on network-shared drives (NFS or Windows networks shares, for 57 example). For this reason, you cannot place your DB databases and 58 environments on network-mounted drives. 59 </p> 60 </div> 61 <div class="navfooter"> 62 <hr /> 63 <table width="100%" summary="Navigation footer"> 64 <tr> 65 <td width="40%" align="left"><a accesskey="p" href="accessmethods.html">Prev</a> </td> 66 <td width="20%" align="center"> 67 <a accesskey="u" href="introduction.html">Up</a> 68 </td> 69 <td width="40%" align="right"> <a accesskey="n" href="environments.html">Next</a></td> 70 </tr> 71 <tr> 72 <td width="40%" align="left" valign="top">Access Methods </td> 73 <td width="20%" align="center"> 74 <a accesskey="h" href="index.html">Home</a> 75 </td> 76 <td width="40%" align="right" valign="top"> Environments</td> 77 </tr> 78 </table> 79 </div> 80 </body> 81</html> 82