65 lines
5.0 KiB
HTML
65 lines
5.0 KiB
HTML
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<meta name="DC.Title" content="Describe access paths for database files" />
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<meta name="abstract" content="These topics discuss the different ways of describing access paths for database files." />
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<title>Describe access paths for database files</title>
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</head>
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<body id="rbafoapath"><a name="rbafoapath"><!-- --></a>
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<!-- Java sync-link --><script language="Javascript" src="../rzahg/synch.js" type="text/javascript"></script>
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<h1 class="topictitle1">Describe access paths for database files</h1>
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<div><p>These topics discuss the different ways of describing access paths
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for database files.</p>
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<p>An access path describes the
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order in which records are to be retrieved. Records in a physical or logical
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file can be retrieved using an arrival sequence access path or a keyed sequence
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access path. For logical files, you can also select and omit records based
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on the value of one or more fields in each record. A key field is a field
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used to arrange the records of a particular type within a file member.</p>
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</div>
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<div>
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<ul class="ullinks">
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<li class="ulchildlink"><strong><a href="rbafoasapa.htm">Use arrival sequence access path for database files</a></strong><br />
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The arrival sequence access path for database files is based on the order in which the records arrive and are stored in the file. This topic discusses what kind of file can use arrival sequence access path and how you can use the path to describe the file.</li>
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<li class="ulchildlink"><strong><a href="rbafoksapa.htm">Use a keyed sequence access path for database files</a></strong><br />
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A keyed sequence access path for database files is based on the contents of the key fields as defined in data description specifications (DDS). This topic describes how the key fields are arranged for the file.</li>
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<li class="ulchildlink"><strong><a href="rbafoeaccp.htm">Use existing access path specifications</a></strong><br />
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The keyword REFACCPTH in data description specifications (DDS) allows you to use another file's access path specifications. When the file is created, the system determines which access path to share.</li>
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<li class="ulchildlink"><strong><a href="rbafofpaccp.htm">Use floating-point fields in database file access paths</a></strong><br />
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The collating sequence for records in a keyed database file depends on the presence of the SIGNED, UNSIGNED, and ABSVAL keywords in data description specifications (DDS). For floating-point fields, the sign is the farthest-left bit, the exponent is next, and the significant is last.</li>
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</ul>
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<div class="familylinks">
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<div class="parentlink"><strong>Parent topic:</strong> <a href="rbafosetup.htm" title="These topics discuss how to set up any iSeries database file, how to describe access paths for a database file, and how to secure a database.">Set up database files</a></div>
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</div>
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<div class="relconcepts"><strong>Related concepts</strong><br />
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<div><a href="rbafoapd.htm" title="When you describe a database file to the system, you describe the two major parts of the file: the record format and the access path. An access path describes the order in which records are to be retrieved. So when you describe an access path, you describe whether it will be a keyed sequence or arrival sequence access path.">Access path description</a></div>
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</div>
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</body>
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</html>
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