58 lines
4.3 KiB
HTML
58 lines
4.3 KiB
HTML
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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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<meta name="DC.Title" content="Improve performance of procedures and functions" />
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<meta name="abstract" content="When creating stored procedures and user-defined functions (UDFs), the SQL procedural language processor on the iSeries does not always generate the most efficient code. However, you can do some changes to reduce the number of database engine calls needed and improve performance." />
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<meta name="description" content="When creating stored procedures and user-defined functions (UDFs), the SQL procedural language processor on the iSeries does not always generate the most efficient code. However, you can do some changes to reduce the number of database engine calls needed and improve performance." />
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<meta name="copyright" content="(C) Copyright IBM Corporation 1998, 2006" />
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<title>Improve performance of procedures and functions</title>
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</head>
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<body id="rbafyudfperf"><a name="rbafyudfperf"><!-- --></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">Improve performance of procedures and functions</h1>
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<div><p>When creating stored procedures and user-defined functions (UDFs),
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the SQL procedural language processor on the iSeries™ does not always generate the
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most efficient code. However, you can do some changes to reduce the number
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of database engine calls needed and improve performance. </p>
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<div class="section"><p>Some changes are in the design of a routine and some are in the
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implementation. For example, differences between how the C language
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compiler handles host variables and the way the SQL procedural processor requires
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the host variables to be handled can cause many calls to the database engine.
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These calls are very expensive and, when done many times, can significantly
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degrade performance.</p>
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</div>
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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="rbafyimplement.htm">Improve implementation of procedures and functions</a></strong><br />
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These recommendations can be seen as simple coding techniques that can help reduce the processing time of a function or procedure. These tips are especially important to follow in functions, as a function will tend to be called multiple times from many different procedures.</li>
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<li class="ulchildlink"><strong><a href="rbafyredesign.htm">Redesign routines for performance</a></strong><br />
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Even following all of the implementation tips, sometimes a procedure or function may still not perform as well as it needs to. In that case, you need to look at the design of the procedure or UDF and see if there are any changes that can be made to improve the performance.</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="rbafyroutines.htm" title="Routines are pieces of code or programs that you can call to perform operations.">Routines</a></div>
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</div>
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</div>
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</body>
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</html>
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