<?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>