97 lines
6.0 KiB
HTML
97 lines
6.0 KiB
HTML
|
<?xml version="1.0" encoding="UTF-8"?>
|
|||
|
|
<!DOCTYPE html
|
|||
|
|
PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
|
|||
|
|
<html lang="en-us" xml:lang="en-us">
|
|||
|
|
<head>
|
|||
|
|
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
|
|||
|
|
<meta name="security" content="public" />
|
|||
|
|
<meta name="Robots" content="index,follow" />
|
|||
|
|
<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))' />
|
|||
|
|
<meta name="DC.Type" content="task" />
|
|||
|
|
<meta name="DC.Title" content="Estimate the size of the journal receiver manually" />
|
|||
|
|
<meta name="abstract" content="Use this procedure to estimate the size of your journal receiver." />
|
|||
|
|
<meta name="description" content="Use this procedure to estimate the size of your journal receiver." />
|
|||
|
|
<meta name="DC.Relation" scheme="URI" content="rzakiplnuseaux.htm" />
|
|||
|
|
<meta name="DC.Relation" scheme="URI" content="rzakiintrusion.htm" />
|
|||
|
|
<meta name="copyright" content="(C) Copyright IBM Corporation 2004, 2006" />
|
|||
|
|
<meta name="DC.Rights.Owner" content="(C) Copyright IBM Corporation 2004, 2006" />
|
|||
|
|
<meta name="DC.Format" content="XHTML" />
|
|||
|
|
<meta name="DC.Identifier" content="rzakimanualestm" />
|
|||
|
|
<meta name="DC.Language" content="en-us" />
|
|||
|
|
<!-- All rights reserved. Licensed Materials Property of IBM -->
|
|||
|
|
<!-- US Government Users Restricted Rights -->
|
|||
|
|
<!-- Use, duplication or disclosure restricted by -->
|
|||
|
|
<!-- GSA ADP Schedule Contract with IBM Corp. -->
|
|||
|
|
<link rel="stylesheet" type="text/css" href="./ibmdita.css" />
|
|||
|
|
<link rel="stylesheet" type="text/css" href="./ic.css" />
|
|||
|
|
<title>Estimate the size of the journal receiver manually</title>
|
|||
|
|
</head>
|
|||
|
|
<body id="rzakimanualestm"><a name="rzakimanualestm"><!-- --></a>
|
|||
|
|
<!-- Java sync-link --><script language="Javascript" src="../rzahg/synch.js" type="text/javascript"></script>
|
|||
|
|
<h1 class="topictitle1">Estimate the size of the journal receiver manually</h1>
|
|||
|
|
<div><p>Use this procedure to estimate the size of your journal receiver.</p>
|
|||
|
|
<div class="section"><p>This procedure assumes the following:</p>
|
|||
|
|
<ul><li>You are journaling after-images only.</li>
|
|||
|
|
<li>You are using a single journal receiver for an entire day's transactions.</li>
|
|||
|
|
<li>You are journaling database physical files only. It does not include estimates
|
|||
|
|
for access path journaling, integrated file system objects, data areas, data
|
|||
|
|
queues, or user-created entries.</li>
|
|||
|
|
<li>You are not using the MINENTDTA parameter to minimize entry-specific data
|
|||
|
|
for the files.</li>
|
|||
|
|
<li>Most of the journal entries are record-level (changes to
|
|||
|
|
records in a file) instead of object-level (like renaming or moving objects,
|
|||
|
|
ALTER TABLE requests, creating and deleting objects, etc).</li>
|
|||
|
|
</ul>
|
|||
|
|
<p>Follow the steps below to estimate the size of a journal receiver:</p>
|
|||
|
|
</div>
|
|||
|
|
<ol><li class="stepexpand" id="rzakimanualestm__LIRECLN"><a name="rzakimanualestm__LIRECLN"><!-- --></a><span>Determine the average record length for all the files
|
|||
|
|
that you plan to journal. If the record lengths vary significantly and the
|
|||
|
|
information is available, use a weighted average based on the relative number
|
|||
|
|
of transactions per file.</span></li>
|
|||
|
|
<li class="stepexpand" id="rzakimanualestm__fixlen"><a name="rzakimanualestm__fixlen"><!-- --></a><span>If you are not minimizing the fixed-length portion
|
|||
|
|
of the journal entry (not specifying RCVSIZOPT(*MINFIXLEN) on the CRTJRN command),
|
|||
|
|
you can specify the data that is included in the fixed-length portion (FIXLENDTA)
|
|||
|
|
of the journal entries. Find the sum of the bytes for the options you are
|
|||
|
|
using. Select the options from the following list:</span> <ul class="simple"><li>*JOB = 26 bytes</li>
|
|||
|
|
<li>*USR = 10 bytes</li>
|
|||
|
|
<li>*PGM = 10 bytes</li>
|
|||
|
|
<li>*PGMLIB = 22 bytes</li>
|
|||
|
|
<li>*SYSSEQ = 8 bytes</li>
|
|||
|
|
<li>*RMTADR = 20 bytes</li>
|
|||
|
|
<li>*THD = 8 bytes</li>
|
|||
|
|
<li>*LUW = 27 bytes</li>
|
|||
|
|
<li>*XID = 140 bytes</li>
|
|||
|
|
</ul>
|
|||
|
|
</li>
|
|||
|
|
<li class="stepexpand" id="rzakimanualestm__number"><a name="rzakimanualestm__number"><!-- --></a><span>Estimate the number of transactions for a day.</span></li>
|
|||
|
|
<li class="stepexpand"><span>The system-created portion of a journal entry is approximately
|
|||
|
|
50 bytes. (It varies by the type of journal entry.)</span></li>
|
|||
|
|
<li class="stepexpand"><span>Estimate the number bytes of auxiliary storage needed for one day's
|
|||
|
|
transactions by using the following formula: </span> <pre>Total bytes needed = (a+b+50)*c</pre>
|
|||
|
|
<p>where:</p>
|
|||
|
|
<ul class="simple"><li>a = the average record length of files (step <a href="#rzakimanualestm__LIRECLN">1</a>)</li>
|
|||
|
|
<li>b = sum of values selected for FIXLENDTA (step <a href="#rzakimanualestm__fixlen">2</a>)</li>
|
|||
|
|
<li>c = number of transactions for a day (step <a href="#rzakimanualestm__number">3</a>)</li>
|
|||
|
|
</ul>
|
|||
|
|
</li>
|
|||
|
|
</ol>
|
|||
|
|
<div class="section"><p>For example:</p>
|
|||
|
|
<ol><li>The average record length for journaled files is 115 bytes.</li>
|
|||
|
|
<li>*JOB, *USR, and *PGM options of FIXLENDTA are selected. Their sum is 46
|
|||
|
|
bytes.</li>
|
|||
|
|
<li>The number of journaled transactions per day is 10 000.</li>
|
|||
|
|
<li>The total bytes needed to journal after-images for a day is: <pre>(115+46+50) * 10 000 = 2 110 000</pre>
|
|||
|
|
</li>
|
|||
|
|
</ol>
|
|||
|
|
</div>
|
|||
|
|
</div>
|
|||
|
|
<div>
|
|||
|
|
<div class="familylinks">
|
|||
|
|
<div class="parentlink"><strong>Parent topic:</strong> <a href="rzakiplnuseaux.htm" title="If you are journaling an object, journal management writes a copy of every object change to the journal receiver. It writes additional entries for object level activity, such as opening and closing the object, adding a member, or changing an object attribute. If you have a busy system and journal many objects, your journal receivers can quickly become very large.">Plan for journal use of auxiliary storage</a></div>
|
|||
|
|
</div>
|
|||
|
|
<div class="relconcepts"><strong>Related concepts</strong><br />
|
|||
|
|
<div><a href="rzakiintrusion.htm" title="You can use the Fixed Length Data (FIXLENDTA) parameter of Create Journal (CRTJRN) and Change Journal (CHGJRN) commands to audit security related activity for journaled objects on your system.">Fixed-length options for journal entries</a></div>
|
|||
|
|
</div>
|
|||
|
|
</div>
|
|||
|
|
</body>
|
|||
|
|
</html>
|