84 lines
6.5 KiB
HTML
84 lines
6.5 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="concept" />
|
|
<meta name="DC.Title" content="Work with access methods for DDM" />
|
|
<meta name="abstract" content="Access methods control what subsets of functions can be performed after a particular remote file is opened. This might mean that an iSeries program, or a group of programs sharing a non-iSeries file, cannot do all the same operations that are possible using a file that is on the local iSeries server." />
|
|
<meta name="description" content="Access methods control what subsets of functions can be performed after a particular remote file is opened. This might mean that an iSeries program, or a group of programs sharing a non-iSeries file, cannot do all the same operations that are possible using a file that is on the local iSeries server." />
|
|
<meta name="DC.subject" content="access method, remote system, file processing differences, differences, remote file processing, relative record number" />
|
|
<meta name="keywords" content="access method, remote system, file processing differences, differences, remote file processing, relative record number" />
|
|
<meta name="DC.Relation" scheme="URI" content="rbae5ddmop.htm" />
|
|
<meta name="DC.Relation" scheme="URI" content="rbae5accessintents.htm" />
|
|
<meta name="DC.Relation" scheme="URI" content="rbae5keyfield.htm" />
|
|
<meta name="DC.Relation" scheme="URI" content="rbae5delrecords.htm" />
|
|
<meta name="DC.Relation" scheme="URI" content="rbae5brp.htm" />
|
|
<meta name="DC.Relation" scheme="URI" content="rbae5varlength.htm" />
|
|
<meta name="copyright" content="(C) Copyright IBM Corporation 1999, 2006" />
|
|
<meta name="DC.Rights.Owner" content="(C) Copyright IBM Corporation 1999, 2006" />
|
|
<meta name="DC.Format" content="XHTML" />
|
|
<meta name="DC.Identifier" content="rbae5amc" />
|
|
<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>Work with access methods for DDM</title>
|
|
</head>
|
|
<body id="rbae5amc"><a name="rbae5amc"><!-- --></a>
|
|
<!-- Java sync-link --><script language="Javascript" src="../rzahg/synch.js" type="text/javascript"></script>
|
|
<h1 class="topictitle1">Work with access methods for DDM</h1>
|
|
<div><p>Access methods control what subsets of functions can be performed
|
|
after a particular remote file is opened. This might mean that an <span class="keyword">iSeries™</span> program, or a group
|
|
of programs sharing a non-<span class="keyword">iSeries</span> file,
|
|
cannot do all the same operations that are possible using a file that is on
|
|
the local <span class="keyword">iSeries server</span>.</p>
|
|
<p>For example, assume that an <span class="keyword">iSeries</span> application
|
|
program opens a keyed file with SHARE(*YES) and performs keyed I/O operations.
|
|
It then calls another program that does relative record number operations
|
|
using the same open data path (ODP) (because SHARE was specified). <dfn class="term">Relative
|
|
record numbers</dfn> specify the relationship between the location of a record
|
|
and the beginning of a database file, member, or subfile. If the first program
|
|
is redirected by an <span class="cmdname">Override with Database File (OVRDBF) </span>command
|
|
to use a remote keyed file on a <span class="keyword">System/36™</span>,
|
|
this scheme no longer works. If a <em>keyed</em> access method is selected,
|
|
record number operations fail. If a <em>record number</em> access method is
|
|
selected, keyed operations fail.</p>
|
|
<p>Notice that when both source and target servers are <span class="keyword">iSeries server</span>s,
|
|
access methods are not used. A potential problem exists when the target server
|
|
is neither an <span class="keyword">iSeries server</span> nor
|
|
a <span class="keyword">System/38™</span>. Notice also that
|
|
the combined-access access method (*COMBINED) is not supported by <span class="keyword">System/36</span>, and probably not by any target
|
|
other than an <span class="keyword">iSeries server</span> or <span class="keyword">System/38</span>.</p>
|
|
</div>
|
|
<div>
|
|
<ul class="ullinks">
|
|
<li class="ulchildlink"><strong><a href="rbae5accessintents.htm">Access intents</a></strong><br />
|
|
When a program opens a file, it must specify how it intends to work with the records in the file: read, add, update, delete, or a combination of these.</li>
|
|
<li class="ulchildlink"><strong><a href="rbae5keyfield.htm">Key field updates</a></strong><br />
|
|
An <span class="keyword">iSeries</span> program
|
|
is allowed to change any part of a data record including key fields. </li>
|
|
<li class="ulchildlink"><strong><a href="rbae5delrecords.htm">Deleted records</a></strong><br />
|
|
On the <span class="keyword">iSeries server</span>,
|
|
a record is marked as deleted by the server.</li>
|
|
<li class="ulchildlink"><strong><a href="rbae5brp.htm">Blocked record processing</a></strong><br />
|
|
If SEQONLY is used to block records sent to a remote server, the records are not sent until the block is full. If a source job is canceled before a block is sent, the records in the block are lost. If blocking is used, the user should make sure a force end of data or close of the file is done before canceling the source job.</li>
|
|
<li class="ulchildlink"><strong><a href="rbae5varlength.htm">Variable-length records</a></strong><br />
|
|
If your <span class="keyword">iSeries</span> source
|
|
server is running OS/400<sup>®</sup> Version 2 Release 1 Modification 1, DDM supports
|
|
variable-length record files as defined in the DDM architecture.</li>
|
|
</ul>
|
|
|
|
<div class="familylinks">
|
|
<div class="parentlink"><strong>Parent topic:</strong> <a href="rbae5ddmop.htm" title="This topic provides task-oriented information and examples that describe various aspects of DDM operation considerations.">Operating considerations for DDM</a></div>
|
|
</div>
|
|
</div>
|
|
</body>
|
|
</html> |