69 lines
3.8 KiB
HTML
69 lines
3.8 KiB
HTML
<?xml version="1.0" encoding="utf-8"?>
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<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
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"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
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<html xmlns="http://www.w3.org/1999/xhtml" lang="en-US" xml:lang="en-us">
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<head>
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<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
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<meta name="dc.language" scheme="rfc1766" content="en-us" />
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<!-- All rights reserved. Licensed Materials Property of IBM -->
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<!-- US Government Users Restricted Rights -->
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<!-- Use, duplication or disclosure restricted by -->
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<!-- GSA ADP Schedule Contract with IBM Corp. -->
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<meta name="dc.date" scheme="iso8601" content="2005-09-19" />
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<meta name="copyright" content="(C) Copyright IBM Corporation 1998, 2006" />
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<meta name="security" content="public" />
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<meta name="Robots" content="index,follow"/>
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<meta http-equiv="PICS-Label" content='(PICS-1.1 "http://www.icra.org/ratingsv02.html" l gen true r (cz 1 lz 1 nz 1 oz 1 vz 1) "http://www.rsac.org/ratingsv01.html" l gen true r (n 0 s 0 v 0 l 0) "http://www.classify.org/safesurf/" l gen true r (SS~~000 1))' />
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<title>Storage Structures</title>
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<link rel="stylesheet" type="text/css" href="ibmidwb.css" />
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<link rel="stylesheet" type="text/css" href="ic.css" />
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</head>
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<body>
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<a id="Top_Of_Page" name="Top_Of_Page"></a><!-- Java sync-link -->
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<script language = "Javascript" src = "../rzahg/synch.js" type="text/javascript"></script>
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<a name="storagestruc"></a>
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<h2 id="storagestruc"><a href="rbafzmst02.htm#ToC_59">Storage Structures</a></h2>
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<p>The iSeries system is an object-based system. All database objects in DB2 UDB for iSeries (tables
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and indexes for example) are objects in i5/OS. The single-level storage manager
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manages all storage of objects of the database, so database specific storage
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structures (for example, table spaces) are unnecessary.</p>
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<p>A distributed table allows data to be spread across different
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database partitions. The partitions included are determined by the nodegroup
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specified when the table is created or altered. A nodegroup is a group of
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one or more iSeries systems. A partitioning map is associated with each nodegroup.
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The partitioning map is used by the database manager to determine which system
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from the nodegroup will store a given row of data. For more information about
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nodegroups and data partitioning see the <a href="../dbmult/rzaf3kickoff.htm">DB2® Multisystem</a> book.</p>
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<p>A table can also include columns that register links to data that are stored
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in external files. The mechanism for this is the DataLink data type. A DataLink
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value which is recorded in a regular table points to a file that is stored
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in an external file server.</p>
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<p>The DB2 File Manager on a file server works in conjunction with DB2 to provide the
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following optional functionality: </p>
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<ul>
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<li>Referential integrity to ensure that files currently linked to DB2 are not deleted
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or renamed.</li>
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<li>Security to ensure that only those with suitable SQL privileges on the
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DataLink column can read the files linked to that column.</li></ul>
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<p>The DataLinker comprises the following facilities:</p>
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<dl>
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<dt class="bold">DataLinks File Manager</dt>
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<dd>Registers all the files in a particular file server that are linked
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to DB2.
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</dd>
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<dt class="bold">DataLinks Filter</dt>
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<dd>Filters file system commands to ensure that registered files are not
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deleted or renamed. Optionally, filters commands to ensure that proper access
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authority exists.
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</dd>
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</dl>
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<hr /><br />
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[ <a href="#Top_Of_Page">Top of Page</a> | <a href="rbafzmstisol.htm">Previous Page</a> | <a href="rbafzmstccseta.htm">Next Page</a> | <a href="rbafzmst02.htm#wq1">Contents</a> |
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<a href="rbafzmstindex.htm#index">Index</a> ]
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<a id="Bot_Of_Page" name="Bot_Of_Page"></a>
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</body>
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