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<!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>When to Replicate Data with Materialized Views</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="When to Replicate Data with Materialized Views" /> <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_intro2ii004.htm" title="Previous" type="text/html" /> <link rel="next" href="tdpii_intro2ii006.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_intro2ii004.htm"><img src="./dcommon/gifs/leftnav.gif" alt="Previous" /><br /> <span class="icon">Previous</span></a> </td> <td align="center"><a href="tdpii_intro2ii006.htm"><img src="./dcommon/gifs/rightnav.gif" alt="Next" /><br /> <span class="icon">Next</span></a></td> </tr> </table> <p><a id="CFHBIEHG" name="CFHBIEHG"></a><a id="TDPII179" name="TDPII179"></a></p> <div class="sect2"><!-- infolevel="all" infotype="General" --> <h1>When to Replicate Data with Materialized Views<a id="sthref9" name="sthref9"></a></h1> <a name="BEGIN" id="BEGIN"></a> <p>It might not always be practical for all users to access data that is stored in a single location. For example, field sales personnel might need access to a price list when they are at a customer site, without immediate access to the corporate databases. They might want to process an order, even if they cannot connect to the primary or master database. These users require a replica of the database or a portion of the database.</p> <p>Unlike Oracle Streams replication, materialized views do not continuously replicate data at all times. A materialized view is a replica of a table or a subset of a table that can be refreshed to a transactionally consistent point in time. During a refresh, only the final values of the changed rows are pulled down and applied to the materialized view, no matter how many updates were applied to the master table. This reduces the amount of time that the remote site must be connected to the master site.</p> <p>Materialized views are especially useful for locations with limited connectivity to the master site. Updatable materialized views allow these locations to function autonomously, even when connectivity is unavailable. When updates are allowed at multiple locations, ownership is typically partitioned in some manner between the locations to prevent conflicting updates. When conflicts are possible, Oracle provides conflict resolution methods that can resolve these conflicts automatically.</p> <p>In addition to supporting disconnected computing, organizations can also use materialized views to improve performance and scalability by providing local access to data and by off loading processing at the primary location. For example, one or more materialized views might be used to off load reporting activity from an order-entry system.</p> <div class="helpinfonotealso"> <h2>Related Topics</h2> <p><a href="tdpii_reppit.htm#BEHHGGIB">Replicating Data Using Materialized Views</a></p> <p><a href="tdpii_intro2ii002.htm#CHDIGBDE">About Data Replication and Integration Features</a></p> </div> </div> <!-- class="sect2" --> <!-- 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. 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