Edit D:\app\Administrator\product\11.2.0\dbhome_1\oc4j\j2ee\oc4j_applications\applications\em\em\online_help\tdpii\tdpii_repcont013.htm
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en"> <head> <meta http-equiv="Content-Type" content="text/html; charset=us-ascii" /> <meta http-equiv="Content-Style-Type" content="text/css" /> <meta http-equiv="Content-Script-Type" content="text/javascript" /> <title>About Two-Database Replication Environments</title> <meta name="generator" content="Oracle DARB XHTML Converter (Mode = ohj/ohw) - Version 5.1.1 Build 005" /> <meta name="date" content="2009-06-04T17:1:1Z" /> <meta name="robots" content="noarchive" /> <meta name="doctitle" content="About Two-Database Replication Environments" /> <meta name="relnum" content="11g Release 2 (11.2)" /> <meta name="partnum" content="E10703-01" /> <link rel="copyright" href="./dcommon/html/cpyr.htm" title="Copyright" type="text/html" /> <link rel="stylesheet" href="./dcommon/css/blafdoc.css" title="Oracle BLAFDoc" type="text/css" /> <link rel="contents" href="toc.htm" title="Contents" type="text/html" /> <link rel="prev" href="tdpii_repcont012.htm" title="Previous" type="text/html" /> <link rel="next" href="tdpii_repcont014.htm" title="Next" type="text/html" /> <script src="./callback.js" type="text/javascript"></script> <noscript>Your browser does not support JavaScript. This help page requires JavaScript to render correctly.</noscript> </head> <body> <div class="zz-skip-header"><a href="#BEGIN">Skip Headers</a></div> <table class="simple oac_no_warn" summary="" cellspacing="0" cellpadding="0" width="100%"> <col width="86%" /> <col width="*" /> <tr valign="bottom"> <td align="left"></td> <td align="center"><a href="tdpii_repcont012.htm"><img src="./dcommon/gifs/leftnav.gif" alt="Previous" /><br /> <span class="icon">Previous</span></a> </td> <td align="center"><a href="tdpii_repcont014.htm"><img src="./dcommon/gifs/rightnav.gif" alt="Next" /><br /> <span class="icon">Next</span></a></td> </tr> </table> <p><a id="CIHGHCGI" name="CIHGHCGI"></a><a id="TDPII190" name="TDPII190"></a></p> <div class="sect3"><!-- infolevel="all" infotype="General" --> <h1>About Two-Database Replication Environments<a id="sthref157" name="sthref157"></a><a id="sthref158" name="sthref158"></a></h1> <a name="BEGIN" id="BEGIN"></a> <p>A <span class="bold">two-database replication environment</span> is one in which only two databases share the replicated database objects. The changes made to replicated database objects at one database are captured and sent directly to the other database, where they are applied. In a two-database replication environment, only one database might allow changes to the database objects, or both databases might allow changes to them.</p> <p>If only one database allows changes to the replicated database objects, then the other database contains read-only replicas of these database objects. This is a <span class="bold">one-way replication environment</span> and typically has the following basic components:</p> <ul> <li> <p>The first database has a capture process or synchronous capture to capture changes to the replicated database objects.</p> </li> <li> <p>The first database has a propagation that sends the captured changes to the other database.</p> </li> <li> <p>The second database has an apply process to apply changes from the first database.</p> </li> <li> <p>For the best performance, each capture process and apply process has its own queue.</p> </li> </ul> <p><a href="#CIHDICJF">Figure: One-Way Replication in a Two-Database Replication Environment</a> shows a two-database replication environment configured for one-way replication.</p> <div class="figure"><a id="CIHDICJF" name="CIHDICJF"></a><a id="TDPII223" name="TDPII223"></a> <p class="titleinfigure">One-Way Replication in a Two-Database Replication Environment</p> <img src="img/tdpii510.gif" alt="Description of this figure follows" title="Description of this figure follows" longdesc="img_text/tdpii510.htm" /><br /> <a id="sthref159" name="sthref159" href="img_text/tdpii510.htm">Description of "One-Way Replication in a Two-Database Replication Environment"</a><br /> <br /></div> <!-- class="figure" --> <p>In a two-database replication environment, both databases can allow changes to the replicated database objects. In this case, both databases capture changes to these database objects and send the changes to the other database, where they are applied. This is a <span class="bold">bi-directional replication environment</span> and typically has the following basic components:</p> <ul> <li> <p>Each database has a capture process or synchronous capture to capture changes to the replicated database objects.</p> </li> <li> <p>Each database has a propagation that sends the captured changes to the other database.</p> </li> <li> <p>Each database has an apply process to apply changes from the other database.</p> </li> <li> <p>For the best performance, each capture process and apply process has its own queue.</p> </li> </ul> <p><a href="#CIHIFIAG">Figure: Bi-Directional Replication in a Two-Database Replication Environment</a> show a two-database replication environment configured for bi-directional replication.</p> <div class="figure"><a id="CIHIFIAG" name="CIHIFIAG"></a><a id="TDPII224" name="TDPII224"></a> <p class="titleinfigure">Bi-Directional Replication in a Two-Database Replication Environment</p> <img src="img/tdpii511.gif" alt="Description of this figure follows" title="Description of this figure follows" longdesc="img_text/tdpii511.htm" /><br /> <a id="sthref160" name="sthref160" href="img_text/tdpii511.htm">Description of "Bi-Directional Replication in a Two-Database Replication Environment"</a><br /> <br /></div> <!-- class="figure" --> <p>Typically, in a bi-directional replication environment, you should configure conflict resolution to keep the replicated database objects synchronized. You can configure a two-database replication environment using Setup Streams Replication Wizard in Oracle Enterprise Manager or the configuration procedures in the <code>DBMS_STREAMS_ADM</code> package.</p> <div class="helpinfonotealso"> <h2>Related Topics</h2> <p><a href="tdpii_repcont021.htm#CIHDBCGD">Tutorial: Configuring Two-Database Replication with Local Capture Processes</a></p> <p><a href="tdpii_repcont022.htm#BABIJCDG">Tutorial: Configuring Two-Database Replication with a Downstream Capture Process</a></p> <p><a href="tdpii_repcont024.htm#BABDEBBA">Tutorial: Configuring Two-Database Replication with Synchronous Captures</a></p> <p><a href="tdpii_repcont010.htm#BABGAACC">About Conflicts and Conflict Resolution</a></p> <p><a href="tdpii_repcont012.htm#CIHGGCCB">About the Common Types of Oracle Streams Replication Environments</a></p> </div> </div> <!-- class="sect3" --> <!-- Start Footer --> <div class="footer"> <table class="simple oac_no_warn" summary="" cellspacing="0" cellpadding="0" width="100%"> <col width="86%" /> <col width="*" /> <tr> <td align="left"><span class="copyrightlogo">Copyright © 2007, 2009, Oracle and/or its affiliates. All rights reserved.</span><br /> <a href="./dcommon/html/cpyr.htm"><span class="copyrightlogo">Legal Notices</span></a></td> <td align="center"><a href="tdpii_repcont012.htm"><img src="./dcommon/gifs/leftnav.gif" alt="Previous" /><br /> <span class="icon">Previous</span></a> </td> <td align="center"><a href="tdpii_repcont014.htm"><img src="./dcommon/gifs/rightnav.gif" alt="Next" /><br /> <span class="icon">Next</span></a></td> </tr> </table> </div> <!-- class="footer" --> </body> </html>
Ms-Dos/Windows
Unix
Write backup
jsp File Browser version 1.2 by
www.vonloesch.de