105 lines
6.6 KiB
HTML
105 lines
6.6 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="reference" />
|
||
|
|
<meta name="DC.Title" content="FRCRATIO parameter" />
|
||
|
|
<meta name="abstract" content="The force write ratio (FRCRATIO) parameter specifies the maximum number of records that can be inserted, updated, or deleted before they are forced into auxiliary (permanent) storage." />
|
||
|
|
<meta name="description" content="The force write ratio (FRCRATIO) parameter specifies the maximum number of records that can be inserted, updated, or deleted before they are forced into auxiliary (permanent) storage." />
|
||
|
|
<meta name="DC.Relation" scheme="URI" content="rbam6expand.htm" />
|
||
|
|
<meta name="DC.Relation" scheme="URI" content="../rzaki/rzakijrnsysperform.htm" />
|
||
|
|
<meta name="copyright" content="(C) Copyright IBM Corporation 1998, 2006" />
|
||
|
|
<meta name="DC.Rights.Owner" content="(C) Copyright IBM Corporation 1998, 2006" />
|
||
|
|
<meta name="DC.Format" content="XHTML" />
|
||
|
|
<meta name="DC.Identifier" content="rbam6frcratioexpand" />
|
||
|
|
<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>FRCRATIO parameter</title>
|
||
|
|
</head>
|
||
|
|
<body id="rbam6frcratioexpand"><a name="rbam6frcratioexpand"><!-- --></a>
|
||
|
|
<!-- Java sync-link --><script language="Javascript" src="../rzahg/synch.js" type="text/javascript"></script>
|
||
|
|
<h1 class="topictitle1">FRCRATIO parameter</h1>
|
||
|
|
<div><p>The force write ratio (FRCRATIO) parameter specifies the maximum
|
||
|
|
number of records that can be inserted, updated, or deleted before they are
|
||
|
|
forced into auxiliary (permanent) storage.</p>
|
||
|
|
<div class="section"><p>The force write ratio ensures that all inserted, updated, or deleted
|
||
|
|
records are written into auxiliary storage at least as often as this parameter
|
||
|
|
specifies. In the event of system failure, the only records likely to be lost
|
||
|
|
would be those that were inserted, updated, or deleted since the last force
|
||
|
|
write operation.</p>
|
||
|
|
<p>The force write ratio is applied to all records inserted,
|
||
|
|
updated, or deleted in the file through the open data path (ODP) to which
|
||
|
|
the force write ratio applies. If two programs are sharing the file, SHARE(*YES),
|
||
|
|
the force write ratio is not applied separately to the set of records inserted,
|
||
|
|
updated, or deleted by each program. It is applied to any combination of records
|
||
|
|
(from both programs) that equals the specified force write ratio parameter
|
||
|
|
value. For example, if a force write ratio of 5 was specified for the file,
|
||
|
|
any combination of five records from the two programs (such as four from one
|
||
|
|
program and one from the other) forces the records to be written to auxiliary
|
||
|
|
storage. If two or more programs are using the file through separate ODPs,
|
||
|
|
the insertions, updates, and deletions from each program are accumulated individually
|
||
|
|
for each ODP.</p>
|
||
|
|
<p>Each database file can have a force write ratio assigned
|
||
|
|
to it. Logical files, which can access data from more than one physical file,
|
||
|
|
can specify a more restrictive force write ratio (a smaller number of records)
|
||
|
|
than that specified for the based-on physical files. However, a logical file
|
||
|
|
cannot specify a <em>less</em> restrictive force write ratio. If a logical
|
||
|
|
file specifies a less restrictive force write ratio than that specified for
|
||
|
|
any of the physical files, the most restrictive force write ratio from the
|
||
|
|
physical files is used for the logical file. For example, if the force write
|
||
|
|
ratios of three physical files are 2, 6, and 8, the force write ratio of a
|
||
|
|
logical file based on these physical files cannot be greater than 2. If no
|
||
|
|
force write ratio is specified for the logical file, 2 is assumed. Thus, each
|
||
|
|
time a program inserts, updates, or deletes two records in the logical file
|
||
|
|
(regardless of which physical files are affected), those records are forced
|
||
|
|
into auxiliary storage.</p>
|
||
|
|
<p>The FRCRATIO number overrides the SEQONLY number
|
||
|
|
specified. For example, if you specify:</p>
|
||
|
|
<pre>OVRDBF ... SEQONLY(*YES 20) FRCRATIO(5)</pre>
|
||
|
|
<p>The value of 20 is overridden and a buffer of five records
|
||
|
|
is used. When FRCRATIO(1) is used, a buffer still exists, but it contains
|
||
|
|
only a single record.</p>
|
||
|
|
<p>Access paths associated with the inserted, updated,
|
||
|
|
and deleted records are written to auxiliary storage only when all the records
|
||
|
|
covered by the access path have been written to auxiliary storage. If only
|
||
|
|
one ODP exists for the file, the access path is forced to auxiliary storage
|
||
|
|
whenever a forced write occurs. If two or more ODPs to the file exist, the
|
||
|
|
access path is written to auxiliary storage whenever all the inserted, updated,
|
||
|
|
and deleted records for all the ODPs have been forced.</p>
|
||
|
|
<div class="note"><span class="notetitle">Note:</span> <ol><li>These rules apply only when a force write ratio of 2 or higher is specified.
|
||
|
|
When a force write ratio of 1 is specified, the access path is not written
|
||
|
|
to auxiliary storage until all the ODPs have been closed. </li>
|
||
|
|
<li>If the file is being recorded in a journal, FRCRATIO(*NONE) should be
|
||
|
|
specified.</li>
|
||
|
|
</ol>
|
||
|
|
</div>
|
||
|
|
</div>
|
||
|
|
<div class="section"><h4 class="sectiontitle">Values allowed</h4><dl><dt class="dlterm">*NONE</dt>
|
||
|
|
<dd>There is no specified ratio; the system determines when the records are
|
||
|
|
written to auxiliary storage.</dd>
|
||
|
|
<dt class="dlterm"><var class="varname">number-of-records-before-force</var></dt>
|
||
|
|
<dd>Specify the number of updated, inserted, or deleted records that are processed
|
||
|
|
before they are explicitly forced to auxiliary storage.</dd>
|
||
|
|
</dl>
|
||
|
|
</div>
|
||
|
|
</div>
|
||
|
|
<div>
|
||
|
|
<div class="familylinks">
|
||
|
|
<div class="parentlink"><strong>Parent topic:</strong> <a href="rbam6expand.htm" title="This section contains the expanded descriptions of some of the parameters commonly used in the CL commands.">Commonly used parameters</a></div>
|
||
|
|
</div>
|
||
|
|
<div class="relinfo"><strong>Related information</strong><br />
|
||
|
|
<div><a href="../rzaki/rzakijrnsysperform.htm">Journal management and system performance</a></div>
|
||
|
|
</div>
|
||
|
|
</div>
|
||
|
|
</body>
|
||
|
|
</html>
|