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diff --git a/site/trunk/site-publish/partialupdate.html b/site/trunk/site-publish/partialupdate.html new file mode 100644 index 0000000000..f124fc940a --- /dev/null +++ b/site/trunk/site-publish/partialupdate.html @@ -0,0 +1,124 @@ + +<!-- + + Licensed to the Apache Software Foundation (ASF) under one or more + contributor license agreements. See the NOTICE file distributed with + this work for additional information regarding copyright ownership. + The ASF licenses this file to You under the Apache License, Version 2.0 + (the "License"); you may not use this file except in compliance with + the License. You may obtain a copy of the License at + + http://www.apache.org/licenses/LICENSE- 2.0 + + Unless required by applicable law or agreed to in writing, software + distributed under the License is distributed on an "AS IS" BASIS, + WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + See the License for the specific language governing permissions and + limitations under the License. +--> + + +<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> +<HTML> + <HEAD> + <!-- generateKeywords macro --> + <META name="description" content="Apache Tuscany"> + <META name="keywords" content="apache, apache tuscany, tuscany, service, services, fabric, soa, service oriented architecture, sca, service component architecture, das, sdo, csa, ruby, opensource"> + <!-- generateKeywords macro end --> + + <LINK type="text/css" rel="stylesheet" href="http://tuscany.apache.org/stylesheets/default.css"> + <LINK rel="SHORTCUT ICON" href="https://cwiki.apache.org/confluence/display/TUSCANY/$images/favicon.ico"> + <TITLE>Apache Tuscany : PartialUpdate</TITLE> + <META http-equiv="Content-Type" content="text/html;charset=UTF-8"></HEAD> + + <BODY onload="init()"> + <!-- topNav macro --> + <TABLE valign="top" border="0" cellspacing="0" cellpadding="0" width="100%" background="http://tuscany.apache.org/images/TuscanyLogoNEW_Text_120px_bg.jpg"> + <TR> + <TD valing="top" align="left"> + <A href="https://cwiki.apache.org/confluence/pages/viewpage.action?spaceKey=TUSCANY&title=$siteroot"><IMG src="http://tuscany.apache.org/images/TuscanyLogoNEW_Text_120px_bg.jpg" height="91" width="25" border="0"></A> + </TD> + <TD> + <A href="http://tuscany.apache.org/"><IMG src="http://tuscany.apache.org/images/TuscanyLogo.jpg" border="0"></A> + </TD> + + <TD width="100%"> + + </TD> + + <!-- Adds the edit page link to the top banner--> + <TD valign="bottom"> + <DIV style="padding: 2px 10px; margin: 0px;"> + <A href="https://cwiki.apache.org/confluence/pages/editpage.action?pageId=52818"> + <IMG src="http://tuscany.apache.org/images/notep_16.gif" height="16" width="16" border="0" align="absmiddle" title="Edit Page"></A> + </DIV> + </TD> + + </TR> + </TABLE> + <!-- topNav macro end --> + + <!-- breadCrumbs macro --> + <TABLE border="0" cellpadding="2" cellspacing="0" width="100%"> + <TR class="topBar"> + <TD align="left" valign="middle" class="topBarDiv" nowrap="true" width="100%"> + <A href="home.html" title="Apache Tuscany">Apache Tuscany</A> > <A href="home.html" title="Home">Home</A> > <A href="das-overview.html" title="DAS Overview">DAS Overview</A> > <A href="das-java.html" title="DAS Java">DAS Java</A> > <A href="das-java-documentation-menu.html" title="DAS Java Documentation Menu">DAS Java Documentation Menu</A> > <A href="das-java-developer-guide.html" title="DAS Java Developer Guide">DAS Java Developer Guide</A> > <A href="rdb-das-java.html" title="RDB DAS Java">RDB DAS Java</A> > <A href="rdb-das-user-guide.html" title="RDB DAS - User Guide">RDB DAS - User Guide</A> > <A href="" title="PartialUpdate">PartialUpdate</A> + </TD> + + <TD align="right" valign="middle" class="topBarDiv" align="left" nowrap="true"> + <A href="http://mail-archives.apache.org/mod_mbox/tuscany-user">User List</A> | <A href="http://mail-archives.apache.org/mod_mbox/tuscany-dev">Dev List</A> | <A href="http://issues.apache.org/jira/browse/Tuscany">Issue Tracker</A> + </TD> + </TR> + </TABLE> + <!-- breadCrumbs macro end --> + + + <TABLE border="0" cellpadding="0" width="100%" bgcolor="#FFFFFF"> + <TR> + <TD align="left" valign="top"> + + <!-- pageContent macro --> + <DIV id="PageContent"> + + <DIV class="pagecontent"> + <DIV class="wiki-content"> + <H1><A name="PartialUpdate-PartialUpdate"></A>PartialUpdate</H1> + +<P>The RDB DAS uses the SDO Change Summary to generate a set of database write operations. Rather than generated a statement to update all columns in a table that maps to a SDO DataObject Type, the DAS generates statements that update ony those columns that map to a modified DataObject property. For example, consider a Customer DataObject that has had the LastName property changed. The <B>partial update</B> statement generated by the DAS will look something like this:</P> +<DIV class="preformatted panel" style="border-width: 1px;"><DIV class="preformattedContent panelContent"> +<PRE>UPDATE CUSTOMER SET LASTNAME = ? WHERE ID = ? +</PRE> +</DIV></DIV> +<P>Rather than a statement that updates all columns like this:</P> +<DIV class="preformatted panel" style="border-width: 1px;"><DIV class="preformattedContent panelContent"> +<PRE>UPDATE CUSTOMER SET FIRSTNAME = ?, SET LASTNAME = ?, SET ADDRESS = ?, SET PHONE = ?, SET AGE = ?, SET SHOESIZE = ? WHERE ID = ? +</PRE> +</DIV></DIV> +<P>There are a couple of very good reasons for using a partial update approach. For one, a performance boost can be realized by applications writing to wide tables. For example, tables with over 100 columns are not unheard of. It can be a huge waste of resource to update 100 columns when only one was modified. Another reason for partial update is that some databases employ <A href="http://en.wikipedia.org/wiki/Database_trigger" class="external-link" rel="nofollow">triggers</A>on specific columns in a table. Partial updates are necessary when column triggers are employed to avoid tripping the trigger on every row update rather than only on updates to the specific column. </P> + </DIV> + </DIV> + </DIV> + <!-- pageContent macro end --> + + </TD> + </TR> + </TABLE> + + <!-- footer macro --> + <SCRIPT src="http://www.google-analytics.com/urchin.js" type="text/javascript"> + </SCRIPT> + <SCRIPT type="text/javascript"> + _uacct = "UA-1174707-5"; + urchinTracker(); + </SCRIPT> + + <A href="http://www.statcounter.com/" target="_blank"><IMG src="http://c26.statcounter.com/counter.php?sc_project=2619156&java=0&security=94bd7e7d&invisible=0" alt="website stats" border="0"></A> + + <DIV class="footer"> + Copyright � 2003-2012, The Apache Software Foundation </BR> + Apache Tuscany and the Apache Tuscany project logo are trademarks of The Apache Software Foundation. + </DIV> + <!-- footer macro end --> + + </BODY> +</HTML> |