1<!--$Id: products.so,v 10.20 2006/12/05 19:12:12 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: The Berkeley DB products</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<a name="2"><!--meow--></a> 12<table width="100%"><tr valign=top> 13<td><b><dl><dt>Berkeley DB Reference Guide:<dd>Introduction</dl></b></td> 14<td align=right><a href="/intro/where.html"><img src="/images/prev.gif" alt="Prev"></a><a href="/toc.html"><img src="/images/ref.gif" alt="Ref"></a><a href="/am_conf/intro.html"><img src="/images/next.gif" alt="Next"></a> 15</td></tr></table> 16<p align=center><b>The Berkeley DB products</b></p> 17<p>Oracle licenses four different products that use the Berkeley DB technology. 18Each product offers a distinct level of database support. It is not 19possible to mix-and-match products, that is, each application or group 20of applications must use the same Berkeley DB product.</p> 21<p>All four products are included in the single Open Source distribution 22of Berkeley DB from Oracle, and building that distribution automatically 23builds all four products. Each product adds new interfaces and services 24to the product that precedes it in the list. As a result, developers 25can download Berkeley DB and build an application that does only single-user, 26read-only database access, and easily add support later for more users 27and more complex database access patterns.</p> 28<p>Users who distribute Berkeley DB must ensure that they are licensed for the 29Berkeley DB interfaces they use. Information on licensing is available from 30Oracle.</p> 31<b>Berkeley DB Data Store</b> 32<p>The Berkeley DB Data Store product is an embeddable, high-performance data store. It 33supports multiple concurrent threads of control (including multiple 34processes and multiple threads of control within a process) reading 35information managed by Berkeley DB. When updates are required, only a single 36thread of control may be using the database. The Berkeley DB Data Store does no locking, 37and so provides no guarantees of correct behavior if more than one 38thread of control is updating the database at a time. The Berkeley DB Data Store is 39intended for use in read-only applications or applications which can 40guarantee no more than one thread of control will ever update the 41database at a time.</p> 42<b>Berkeley DB Concurrent Data Store</b> 43<p>The Berkeley DB Concurrent Data Store product adds multiple-reader, single writer capabilities to 44the Berkeley DB Data Store product, supporting applications that need concurrent updates 45and do not want to implement their own locking protocols. Berkeley DB Concurrent Data Store is 46intended for applications that require occasional write access to a 47database that is largely used for reading.</p> 48<b>Berkeley DB Transactional Data Store</b> 49<p>The Berkeley DB Transactional Data Store product adds full transactional support and recoverability 50to the Berkeley DB Data Store product. Berkeley DB Transactional Data Store is intended for applications that require 51industrial-strength database services, including excellent performance 52under high-concurrency workloads with a mixture of readers and writers, 53the ability to commit or roll back multiple changes to the database at 54a single instant, and the guarantee that even in the event of a 55catastrophic system or hardware failure, any committed database changes 56will be preserved.</p> 57<b>Berkeley DB High Availability</b> 58<p>The Berkeley DB High Availability product support for data replication. A single master system 59handles all updates, and distributes them to as many replicas as the 60application requires. All replicas can handle read requests during 61normal processing. If the master system fails for any reason, one of 62the replicas takes over as the new master system, and distributes 63updates to the remaining replicas.</p> 64<table width="100%"><tr><td><br></td><td align=right><a href="/intro/where.html"><img src="/images/prev.gif" alt="Prev"></a><a href="/toc.html"><img src="/images/ref.gif" alt="Ref"></a><a href="/am_conf/intro.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