<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html><!-- InstanceBegin template="../../Templates/DocTemp.dwt" codeOutsideHTMLIsLocked="false" -->
<head>
<!-- InstanceBeginEditable name="doctitle" -->
<title>Omnidex Concepts - Index Maintenance - Updating the Indexes</title>
<!-- InstanceEndEditable --> 
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">
<link href="../../docs.css" rel="stylesheet" type="text/css">
<script language="JavaScript1.2" src="../../docs.js"></script>
<!-- InstanceBeginEditable name="head" --><!-- InstanceEndEditable -->
</head>

<body>
<table width="100%" class="lightblue" border="0" cellspacing="0" cellpadding="0">
  <tr>
    <td><a href="http://www.omnidex.com"><img src="../../images/flatlogo.gif" width="95" height="25" hspace="3" vspace="3" border="0"></a></td>
    <td><img src="../../images/omnidex.gif" width="109" height="25" hspace="3" vspace="3"></td>
    <td align="right" valign="top"><p class="banner"><a href="../../Contents.htm">Contents</a> 
        | <a href="../../Quick%20Links.htm">Quick Links</a></p></td>
  </tr>
</table>
<table width="100%" border="0" cellspacing="0" cellpadding="0">
  <tr> 
    <td width="175" class="bar"><p class="banner">&nbsp;</p></td>
    <td align="right" class="bar"> <!-- InstanceBeginEditable name="Section Title" -->
      <h1>Omnidex Concepts - Index Maintenance</h1>
      <!-- InstanceEndEditable --></td>
  </tr>
  <tr> 
    <td width="175" class="left1 lightblue"><img src="../../images/blank.gif" width="10" height="20"> 
    </td>
    <td valign="top" class="left1 lightblue">&nbsp; </td>
  </tr>
  <tr> 
    <td width="175" valign="top" class="left"><!-- InstanceBeginEditable name="leftnav" --> 
      <p><a href="#realtime">Real-Time Indexing</a></p>
      <p><a href="#batch">Batch Indexing</a></p>
      <p><a href="#deferred">Deferred Indexing with ODXAIM</a></p>
      <p class="line">&nbsp;</p>
      <p><a href="Index%20Maintenance.htm">Index Maintenance</a></p>
      <p>&nbsp;</p>
      <!-- InstanceEndEditable --></td>
    <td valign="top" class="content"> <!-- InstanceBeginEditable name="Content" --> 
      <h2>Updating the Indexes</h2>
      <p>With Omnidex indexing, many options are available for updating indexes 
        as data changes.</p>
      <p>When indexing needs to be performed immediately after a record is changed, 
        real-time indexing is required and can be implemented in both synchronous 
        and asynchronous fashions. Synchronous indexing is the easiest to implement, 
        while asynchronous indexing maximizes throughput of transactions. The 
        choice of options depends on how many keys are involved, how much activity 
        must be indexed and the complexity of implementing one over the other.</p>
      <p><a href="#realtime"><img src="../../images/arrow2.gif" width="10" height="10" border="0">Real-Time 
        Indexing</a></p>
      <p><a href="#batch"><img src="../../images/arrow2.gif" width="10" height="10" border="0">Batch 
        Indexing</a></p>
      <p><a href="#deferred"><img src="../../images/arrow2.gif" width="10" height="10" border="0">Deferred 
        Indexing with ODXAIM</a></p>
      <p class="line">&nbsp;</p>
      <h3><a name="realtime" id="realtime"></a>Indexing in Real-Time</h3>
      <p>When indexing volatile online databases, it is usually desirable to index 
        in real-time. Update activity is not as intense as during a batch update, 
        but response time to the user must be reasonable to maximize efficiency 
        of the data entry personnel. Consequently, the options for maintaining 
        indexes depend on the level of activity and the number of keys being indexed 
        on the affected tables.</p>
      <p>For online activity with a relatively small number of updates, real-time, 
        synchronous indexing is the preferred option. This is true even where 
        many keys are involved. The slight hesitation involved with indexing a 
        number of columns is a small price to pay for the time that is saved every 
        time the record is searched on and retrieved in the future.</p>
      <p>As the number of transactions or the number of keys increases to a point 
        where response time is adversely affected, real-time, asynchronous indexing 
        using <a href="../../Utilities/ODXAIM/ODXAIM.htm">ODXAIM</a>, may be a 
        better solution. This allows data updates to be completed without regard 
        to the index updates, which are completed in the background.</p>
      <p>If asynchronous updating is not desired for some reason, then <a href="#batch">indexing 
        in batch</a> is always an option. However, batch updates require exclusive 
        access to the Omnidex indexes which precludes users from updating Omnidex-indexed 
        data during the index build process.</p>
      <p class="line">&nbsp;</p>
      <h3><a name="batch" id="batch"></a>Indexing in Batch</h3>
      <p>Databases that are very static, such as data warehouses, data marts and 
        other archived data structures are typically updated in periodic batches 
        rather than through online data entry. As such, the methods best suited 
        for indexing these changes are typically batch-oriented, and depend on 
        the overall database size, the frequency of updates and the relative number 
        of records.</p>
      <p>If the frequency of updating is rare, say quarterly or yearly, then the 
        choice is usually to re-index after the batch updates. Even in large databases, 
        indexing can be completed at very high rates of speed with Omnidex, freeing 
        the database for online access for the rest of the quarter or year.</p>
      <p>If the database is updated more frequently, say weekly or nightly, then 
        database size and the volume of updates play a part in the decision. Again, 
        if the database can be indexed in a night or a weekend, and the batch 
        window allows for the database to be unavailable for that time, then indexing 
        in batch is usually the best (fastest and easiest) choice.</p>
      <p class="line">&nbsp;</p>
      <h3><a name="deferred"></a>Deferred Indexing with ODXAIM</h3>
      <p><a href="../../Utilities/ODXAIM/ODXAIM.htm">ODXAIM</a>, Omnidex Automatic 
        Index Maintenance, automatically maintains index synchronization for applications 
        that do not use OmniAccess, using database triggers to signal when an 
        update has occurred. It also enables transaction management on the Omnidex 
        indexes.</p>
      <ul>
        <li>Applications like SQL Plus work directly with the underlying database 
          management system and are unaware of Omnidex or the Omnidex indexes. 
          Normally, when data is updated through SQL Plus, the Omnidex indexes 
          remain unchanged. Through database triggers, ODXAIM automatically updates 
          the indexes with these changes. </li>
        <li>If transaction management is set up on a table installed with Omnidex 
          indexes, ODXAIM causes those indexes to inherit the transaction management. 
          When a change is made to the table, a record is written to a table named 
          ODXTRANS. ODXAIM reads the ODXTRANS table and updates the indexes accordingly. 
          If the original transaction fails, the record is never written to ODXTRANS.</li>
      </ul>
      <p>With ODXAIM, indexes are not maintained in real-time. However, the delay 
        is minimal, a few minutes or less, and the performance gain to the update 
        application can be considerable.</p>
      <p>&nbsp;</p>
      <p>&nbsp;</p>
      <!-- InstanceEndEditable --><P align="right"><a href="#">Top</a> </P>
	  </td>
  </tr>
  <tr>
    <td width="175" class="bbar">
<p>&nbsp;</p></td>
    <td align="right" valign="middle" class="bbar"> <p class="banner">Omnidex 
        Version 4.1 Build 1 - E10.04 - Dynamic Information Systems Corporation 
        - Copyright &copy; 2004</p></td>
  </tr>
</table>
<div class="menu0" id="m1" onMouseOver="changeClass('menu1','m1'); changeVisibility('visible','s1');" onMouseOut="changeClass('menu0','m1'); changeVisibility('hidden','s1');"> 
  <a href="../../index.htm">Home</a></div>      
<div class="menu0" id="m2" onMouseOver="changeClass('menu1','m2'); changeVisibility('visible','s2');" onMouseOut="changeClass('menu0','m2'); changeVisibility('hidden','s2');"> 
  <a href="../../Omnidex%20Concepts/Omnidex%20Overview.htm">Omnidex</a></div>      
<div class="menu0" id="m3" onMouseOver="changeClass('menu1','m3'); changeVisibility('visible','s3');" onMouseOut="changeClass('menu0','m3'); changeVisibility('hidden','s3');"> 
  <a href="../../Getting%20Started/Getting%20Started.htm">Getting Started </a></div>      
<div class="menu0" id="m4" onMouseOver="changeClass('menu1','m4'); changeVisibility('visible','s4');" onMouseOut="changeClass('menu0','m4'); changeVisibility('hidden','s4');"> 
  <a href="../../Development/Development.htm">Development</a></div>      
<div class="menu0" id="m5" onMouseOver="changeClass('menu1','m5'); changeVisibility('visible','s5');" onMouseOut="changeClass('menu0','m5'); changeVisibility('hidden','s5');"> 
  <a href="../../Utilities/Utilities.htm">Utilities</a></div>      
<div class="menu0" id="m6" onMouseOver="changeClass('menu1','m6'); changeVisibility('visible','s6');" onMouseOut="changeClass('menu0','m6'); changeVisibility('hidden','s6');"> 
  <a href="../../Appendix/Appendix.htm">Appendix</a></div>
    <td>&nbsp;</td>
  </tr>
</table> 
<table id="s1" border="0" cellspacing="0" cellpadding="0" onMouseOver="changeClass('menu1','m1'); changeVisibility('visible','s1');" onMouseOut="changeClass('menu0','m1'); changeVisibility('hidden','s1');">
  <tr> 
    <td id="s11" class="menu1" onMouseOver="changeClass('menu0','s11');" onMouseOut="changeClass('menu1','s11');"><a href="../../Whats%20New.htm">What's 
      New!</a></td>
  </tr>
  <tr> 
    <td id="s12" class="menu1" onMouseOver="changeClass('menu0','s12');" onMouseOut="changeClass('menu1','s12');"><a href="../../Quick%20Links.htm">Quick 
      Links</a></td>
  </tr>
  <tr> 
    <td id="s13" class="menu1" onMouseOver="changeClass('menu0','s13');" onMouseOut="changeClass('menu1','s13');"><a href="../../Contents.htm">Contents</a></td>
  </tr>
</table>
<table id="s2" border="0" cellspacing="0" cellpadding="0" onMouseOver="changeClass('menu1','m2'); changeVisibility('visible','s2');" onMouseOut="changeClass('menu0','m2'); changeVisibility('hidden','s2');">
  <tr> 
    <td id="s21" class="menu1" onMouseOver="changeClass('menu0','s21');" onMouseOut="changeClass('menu1','s21');"><a href="../../Omnidex%20Concepts/Features/Features.htm">Features</a></td>
  </tr>
  <tr> 
    <td id="s22" class="menu1" onMouseOver="changeClass('menu0','s22');" onMouseOut="changeClass('menu1','s22');"><a href="../../Omnidex%20Concepts/Indexing%20Strategies/Indexing%20Strategies.htm">Indexing 
      Strategies</a></td>
  </tr>
  <tr> 
    <td id="s23" class="menu1" onMouseOver="changeClass('menu0','s23');" onMouseOut="changeClass('menu1','s23');"><a href="../../Omnidex%20Concepts/Indexing%20Options/Indexing%20Options.htm">Indexing 
      Options </a></td>
  </tr>
  <tr> 
    <td id="s24" class="menu1" onMouseOver="changeClass('menu0','s24');" onMouseOut="changeClass('menu1','s24');"><a href="../../Omnidex%20Concepts/Index%20Maintenance/Index%20Maintenance.htm">Index 
      Maintenance </a></td>
  </tr>
  <tr> 
    <td id="s25" class="menu1" onMouseOver="changeClass('menu0','s25');" onMouseOut="changeClass('menu1','s25');"><a href="../../Omnidex%20Concepts/Partitioning/Partitioning.htm">Optimization</a></td>
  </tr>
  <tr> 
    <td id="s26" class="menu1" onMouseOver="changeClass('menu0','s26');" onMouseOut="changeClass('menu1','s26');"><a href="../../Omnidex%20Concepts/Index%20Maintenance/Index%20Maintenance.htm">Partitioning</a></td>
  </tr>
  <tr> 
    <td id="s27" class="menu1" onMouseOver="changeClass('menu0','s27');" onMouseOut="changeClass('menu1','s27');"><a href="../../Omnidex%20Concepts/Text/Omnidex%20Text.htm">Omnidex Text</a></td>
  </tr>
</table>
<table id="s3" border="0" cellspacing="0" cellpadding="0" onMouseOver="changeClass('menu1','m3'); changeVisibility('visible','s3');" onMouseOut="changeClass('menu0','m3'); changeVisibility('hidden','s3');">
  <tr> 
    <td id="s31" class="menu1" onMouseOver="changeClass('menu0','s31');" onMouseOut="changeClass('menu1','s31');"><a href="../../Getting%20Started/1%20-%20Installation%20and%20Setup.htm">Server 
      Setup Guides</a></td>
  </tr>
  <tr> 
    <td id="s32" class="menu1" onMouseOver="changeClass('menu0','s32');" onMouseOut="changeClass('menu1','s32');"><a href="../../Getting%20Started/Omnidex%20Client/Windows%20Client.htm">Windows 
      Client</a></td>
  </tr>
  <tr> 
    <td id="s33" class="menu1" onMouseOver="changeClass('menu0','s33');" onMouseOut="changeClass('menu1','s33');"><a href="../../Database%20Platforms/Supported%20Database%20Platforms.htm">Database 
      Platforms </a></td>
  </tr>
  <tr> 
    <td id="s34" class="menu1" onMouseOver="changeClass('menu0','s34');" onMouseOut="changeClass('menu1','s34');"><a href="../../Environment%20Catalog/Environment%20Catalog.htm">Environment 
      Catalog</a> </td>
  </tr>
</table>
<table id="s4" border="0" cellspacing="0" cellpadding="0" onMouseOver="changeClass('menu1','m4'); changeVisibility('visible','s4');" onMouseOut="changeClass('menu0','m4'); changeVisibility('hidden','s4');">
  <tr> 
    <td id="s41" class="menu1" onMouseOver="changeClass('menu0','s41');" onMouseOut="changeClass('menu1','s41');"><a href="../../SQL%20Reference/SQL%20Reference.htm">SQL 
      Reference</a> </td>
  </tr>
  <tr> 
    <td id="s42" class="menu1" onMouseOver="changeClass('menu0','s42');" onMouseOut="changeClass('menu1','s42');"><a href="../../Development/ODBC/ODBC.htm">ODBC</a></td>
  </tr>
  <tr> 
    <td id="s43" class="menu1" onMouseOver="changeClass('menu0','s43');" onMouseOut="changeClass('menu1','s43');"><a href="../../Development/JDBC/JDBC.htm">JDBC</a></td>
  </tr>
  <tr> 
    <td id="s44" class="menu1" onMouseOver="changeClass('menu0','s44');" onMouseOut="changeClass('menu1','s44');"><a href="../../Development/OmniAccess%20API/OmniAccess%20API.htm">OmniAccess 
      API</a></td>
  </tr>
  <tr> 
    <td id="s45" class="menu1" onMouseOver="changeClass('menu0','s45');" onMouseOut="changeClass('menu1','s45');"><a href="../../Development/Debugging/OMNIDEX_DEBUG.htm">Debugging</a></td>
  </tr>
</table>
<table id="s5" border="0" cellspacing="0" cellpadding="0" onMouseOver="changeClass('menu1','m5'); changeVisibility('visible','s5');" onMouseOut="changeClass('menu0','m5'); changeVisibility('hidden','s5');">
  <tr> 
    <td id="s51" class="menu1" onMouseOver="changeClass('menu0','s51');" onMouseOut="changeClass('menu1','s51');"><A href="../../Utilities/DBINSTAL/DBINSTAL.htm">DBINSTAL</A></td>
  </tr>
  <tr> 
    <td id="s52" class="menu1" onMouseOver="changeClass('menu0','s52');" onMouseOut="changeClass('menu1','s52');"><a href="../../Utilities/DSEDIT/DSEDIT.htm">DSEDIT</a></td>
  </tr>
  <tr> 
    <td id="s53" class="menu1" onMouseOver="changeClass('menu0','s53');" onMouseOut="changeClass('menu1','s53');"><a href="../../Utilities/NSADMIN/NSADMIN.htm">NSADMIN</a></td>
  </tr>
  <tr> 
    <td id="s54" class="menu1" onMouseOver="changeClass('menu0','s54');" onMouseOut="changeClass('menu1','s54');"><a href="../../Utilities/OACOMP/OACOMP.htm">OACOMP</a></td>
  </tr>
  <tr> 
    <td id="s55" class="menu1" onMouseOver="changeClass('menu0','s55');" onMouseOut="changeClass('menu1','s55');"><a href="../../Utilities/OADECOMP/OADECOMP.htm">OADECOMP</a></td>
  </tr>
  <tr> 
    <td id="s56" class="menu1" onMouseOver="changeClass('menu0','s56');" onMouseOut="changeClass('menu1','s56');"><a href="../../Utilities/OAHELPER/OAHELPER.htm">OAHELPER</a></td>
  </tr>
  <tr> 
    <td id="s57" class="menu1" onMouseOver="changeClass('menu0','s57');" onMouseOut="changeClass('menu1','s57');"><A href="../../Utilities/ODXAIM/ODXAIM.htm">ODXAIM</A></td>
  </tr>
  <tr> 
    <td id="s58" class="menu1" onMouseOver="changeClass('menu0','s58');" onMouseOut="changeClass('menu1','s58');"><a href="../../Utilities/ODXMAKE/ODXMAKE.htm">ODXMAKE</a></td>
  </tr>
  <tr> 
    <td id="s59" class="menu1" onMouseOver="changeClass('menu0','s59');" onMouseOut="changeClass('menu1','s59');"><a href="../../Utilities/ODXNET/ODXNET.htm">ODXNET</a></td>
  </tr>
  <tr> 
    <td id="s510" class="menu1" onMouseOver="changeClass('menu0','s510');" onMouseOut="changeClass('menu1','s510');"><A href="../../Utilities/ODXQUERY/ODXQUERY.htm">ODXQUERY</A></td>
  </tr>
  <tr> 
    <td id="s511" class="menu1" onMouseOver="changeClass('menu0','s511');" onMouseOut="changeClass('menu1','s511');"><a href="../../Utilities/ODXSQL/ODXSQL.htm">ODXSQL</a></td>
  </tr>
  <tr> 
    <td id="s512" class="menu1" onMouseOver="changeClass('menu0','s512');" onMouseOut="changeClass('menu1','s512');"><a href="../../Utilities/REGMAINT/REGMAINT.htm">REGMAINT</a></td>
  </tr>
  <tr> 
    <td id="s513" class="menu1" onMouseOver="changeClass('menu0','s513');" onMouseOut="changeClass('menu1','s513');"><A href="../../Utilities/REGTEST/REGTEST.htm">REGTEST</A></td>
  </tr>
  <tr> 
    <td id="s514" class="menu1" onMouseOver="changeClass('menu0','s514');" onMouseOut="changeClass('menu1','s514');"><a href="../../Utilities/SNOWGEN/SNOWGEN.htm">SNOWGEN</a></td>
  </tr>
  <tr> 
    <td id="s515" class="menu1" onMouseOver="changeClass('menu0','s515');" onMouseOut="changeClass('menu1','s515');"><a href="../../Utilities/SYSINFO/SYSINFO.htm">SYSINFO</a></td>
  </tr>
  <tr> 
    <td id="s516" class="menu1" onMouseOver="changeClass('menu0','s516');" onMouseOut="changeClass('menu1','s516');"><a href="../../Utilities/VERSIONS/VERSIONS.htm">VERSIONS</a></td>
  </tr>
  <tr> 
    <td id="s517" class="menu1" onMouseOver="changeClass('menu0','s517');" onMouseOut="changeClass('menu1','s517');"><a href="../../Utilities/VIEWGEN/VIEWGEN.htm">VIEWGEN</a></td>
  </tr>
</table>
<table id="s6" border="0" cellspacing="0" cellpadding="0" onMouseOver="changeClass('menu1','m6'); changeVisibility('visible','s6');" onMouseOut="changeClass('menu0','m6'); changeVisibility('hidden','s6');">
  <tr> 
    <td id="s61" class="menu1" onMouseOver="changeClass('menu0','s61');" onMouseOut="changeClass('menu1','s61');"><a href="../../Appendix/Cardinality.htm">Cardinality</a></td>
  </tr>
  <tr> 
    <td id="s62" class="menu1" onMouseOver="changeClass('menu0','s62');" onMouseOut="changeClass('menu1','s62');"><a href="../../Appendix/Date%20Formats.htm">Date 
      Formats </a></td>
  </tr>
  <tr> 
    <td id="s63" class="menu1" onMouseOver="changeClass('menu0','s63');" onMouseOut="changeClass('menu1','s63');"><a href="../../Appendix/Environment%20Variables.htm">Environment 
      Variables </a></td>
  </tr>
  <tr> 
    <td id="s64" class="menu1" onMouseOver="changeClass('menu0','s64');" onMouseOut="changeClass('menu1','s64');"><a href="../../Appendix/File%20Name%20Handling.htm">File 
      Name Handling</a></td>
  </tr>
  <tr> 
    <td id="s65" class="menu1" onMouseOver="changeClass('menu0','s65');" onMouseOut="changeClass('menu1','s65');"><a href="../../Appendix/Glossary%20A.htm">Glossary</a></td>
  </tr>
  <tr> 
    <td id="s66" class="menu1" onMouseOver="changeClass('menu0','s66');" onMouseOut="changeClass('menu1','s66');"><a href="../../Appendix/Null.htm">Null</a></td>
  </tr>
  <tr> 
    <td id="s67" class="menu1" onMouseOver="changeClass('menu0','s67');" onMouseOut="changeClass('menu1','s67');"><a href="../../Appendix/OAGLOBAL.htm">OAGLOBAL</a></td>
  </tr>
  <tr> 
    <td id="s68" class="menu1" onMouseOver="changeClass('menu0','s68');" onMouseOut="changeClass('menu1','s68');"><a href="../../Appendix/Operating%20Limits.htm">Operating 
      Limits</a></td>
  </tr>
  <tr> 
    <td id="s69" class="menu1" onMouseOver="changeClass('menu0','s69');" onMouseOut="changeClass('menu1','s69');"><a href="../../Appendix/Provided%20Managed%20Synonym%20Lists.htm">Managed 
      Synonym Lists</a></td>
  </tr>
  <tr> 
    <td id="s70" class="menu1" onMouseOver="changeClass('menu0','s70');" onMouseOut="changeClass('menu1','s70');"><a href="../../Appendix/Reserved%20Words.htm">Reserved 
      Words</a></td>
  </tr>
  <tr> 
    <td id="s71" class="menu1" onMouseOver="changeClass('menu0','s71');" onMouseOut="changeClass('menu1','s71');"><a href="../../Appendix/Supported%20Datatypes.htm">Supported 
      Data Types</a></td>
  </tr>
</table>
<p>&nbsp;</p>
</body>
<!-- InstanceEnd --></html>
