63 lines
3.8 KiB
HTML
63 lines
3.8 KiB
HTML
<?xml version="1.0" encoding="UTF-8"?>
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<!DOCTYPE html
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PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
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<html lang="en-us" xml:lang="en-us">
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<head>
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<meta name="DC.Type" content="concept" />
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<meta name="DC.Title" content="Storage pool paging option effect on database performance" />
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<meta name="abstract" content="The paging option of shared pools can have a significant impact on the performance of reading and changing database files." />
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<meta name="description" content="The paging option of shared pools can have a significant impact on the performance of reading and changing database files." />
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<meta name="DC.Relation" scheme="URI" content="rbafopreopn.htm" />
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<meta name="DC.Relation" scheme="URI" content="../rzahx/rzahx1.htm" />
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<meta name="copyright" content="(C) Copyright IBM Corporation 1998, 2006" />
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<meta name="DC.Identifier" content="rbafostrplpg" />
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<title>Storage pool paging option effect on database performance</title>
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</head>
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<body id="rbafostrplpg"><a name="rbafostrplpg"><!-- --></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">Storage pool paging option effect on database performance</h1>
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<div><p>The paging option of shared pools can have a significant impact
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on the performance of reading and changing database files. </p>
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<div class="p"><ul><li>A paging option of *FIXED causes the program to minimize the amount of
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memory it uses by: <ul><li>Transferring data from auxiliary storage to main memory in smaller blocks</li>
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<li>Writing file changes (updates to existing records or newly added records)
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to auxiliary storage frequently</li>
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</ul>
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This option allows the system to perform much like it did
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before the paging option was added.</li>
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<li>A paging option of *CALC might improve how the program performs when it
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reads and updates database files. In cases where there is sufficient memory
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available within a shared pool, the program might: <ul><li>Transfer larger blocks of data to memory from auxiliary storage.</li>
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<li>Write changed data to auxiliary storage less frequently.</li>
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</ul>
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The paging operations done on database files vary dynamically based on
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file use and memory availability. Frequently referenced files are more likely
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to remain resident than those less often accessed. The memory is used somewhat
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like a cache for popular data. The overall number of I/O operations might
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be reduced using the *CALC paging option.</li>
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</ul>
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</div>
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</div>
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<div>
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<div class="familylinks">
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<div class="parentlink"><strong>Parent topic:</strong> <a href="rbafopreopn.htm" title="These topics describe the file processing parameters and other methods or considerations that can affect database file processing.">Database file processing: Runtime considerations</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="../rzahx/rzahx1.htm">Performance</a></div>
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</div>
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</div>
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</body>
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