ibm-information-center/dist/eclipse/plugins/i5OS.ic.rbam6_5.4.0.1/dtaas.htm

129 lines
8.3 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="Use data areas" />
<meta name="abstract" content="A data area is an object used to hold data for access by any job running on the system." />
<meta name="description" content="A data area is an object used to hold data for access by any job running on the system." />
<meta name="DC.subject" content="communicate, between procedure, using data area, data area, data area, description, initial value" />
<meta name="keywords" content="communicate, between procedure, using data area, data area, data area, description, initial value" />
<meta name="DC.Relation" scheme="URI" content="clpgcomm.htm" />
<meta name="DC.Relation" scheme="URI" content="lclda.htm" />
<meta name="DC.Relation" scheme="URI" content="grpda.htm" />
<meta name="DC.Relation" scheme="URI" content="pipda.htm" />
<meta name="DC.Relation" scheme="URI" content="remdta.htm" />
<meta name="DC.Relation" scheme="URI" content="crtda.htm" />
<meta name="DC.Relation" scheme="URI" content="dalal.htm" />
<meta name="DC.Relation" scheme="URI" content="disda.htm" />
<meta name="DC.Relation" scheme="URI" content="chgda.htm" />
<meta name="DC.Relation" scheme="URI" content="retda.htm" />
<meta name="DC.Relation" scheme="URI" content="excop.htm" />
<meta name="DC.Relation" scheme="URI" content="crdae.htm" />
<meta name="DC.Relation" scheme="URI" content="../cl/crtdtaara.htm" />
<meta name="DC.Relation" scheme="URI" content="../cl/rtvdtaara.htm" />
<meta name="DC.Relation" scheme="URI" content="../cl/chgdtaara.htm" />
<meta name="DC.Relation" scheme="URI" content="../cl/dspdtaara.htm" />
<meta name="DC.Relation" scheme="URI" content="../cl/dltdtaara.htm" />
<meta name="DC.Relation" scheme="URI" content="../rzaki/rzakikickoff.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="dtaas" />
<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>Use data areas</title>
</head>
<body id="dtaas"><a name="dtaas"><!-- --></a>
<!-- Java sync-link --><script language="Javascript" src="../rzahg/synch.js" type="text/javascript"></script>
<h1 class="topictitle1">Use data areas</h1>
<div><p>A data area is an object used to hold data for access by any job
running on the system.</p>
<div class="section"> <p>A data area can be used whenever you need to store information
of limited size, independent of the existence of procedures or files. Typical
uses of data areas are: </p>
<ul><li>To provide an area (perhaps within each job's QTEMP library) to pass information
within a job.</li>
<li>To provide a field that is easily and frequently changed to control references
within a job, such as: <ul><li>Supplying the next order number to be assigned</li>
<li>Supplying the next check number</li>
<li>Supplying the next save/restore media volume to be used</li>
</ul>
</li>
<li>To provide a constant field for use in several jobs, such as a tax rate
or distribution list.</li>
<li>To provide limited access to a larger process that requires the data area.
A data area can be locked to a single user, thus preventing other users from
processing at the same time.</li>
</ul>
<p>To create a data area other than a local or group data area, use the <span class="cmdname">Create
Data Area (CRTDTAARA)</span> command. By doing this, you create a separate
object in a specific library, and you can initialize it to a value. To use
the value in a CL procedure or program, use a <span class="cmdname">Retrieve Data Area
(RTVDTAARA)</span> command to bring the current value into a variable in
your procedure or program. If you change this value in your CL procedure or
program and want to return the new value to the data area, use the <span class="cmdname">Change
Data Area (CHGDTAARA)</span> command.</p>
<p>To display the current value,
use the <span class="cmdname">Display Data Area (DSODTAARA)</span> command. You can
delete a data area using the <span class="cmdname">Delete Data Area (DLTDTAARA)</span> command.</p>
<p>You
can journal your data areas. This allows you to recover the object to a consistent
state, even if the object was in the middle of some change action when the
abnormal IPL or crash occurred. Journaling also provides for replication of
the data area journal to a remote system (using remote journal for instance).
This lets the system reproduce the actions in a similar environment to replicate
the application work.</p>
</div>
</div>
<div>
<ul class="ullinks">
<li class="ulchildlink"><strong><a href="lclda.htm">Local data area</a></strong><br />
A local data area is created for each job in the system, including autostart jobs, jobs started on the system by a reader, and subsystem monitor jobs.</li>
<li class="ulchildlink"><strong><a href="grpda.htm">Group data area</a></strong><br />
The system creates a group data area when an interactive job becomes
a group job (using the <span class="cmdname">Change Group Attributes (CHGGRPA)</span> command). </li>
<li class="ulchildlink"><strong><a href="pipda.htm">Program Initialization Parameter (PIP) data area</a></strong><br />
A PIP data area (PDA) is created for each prestart job when the job is started.</li>
<li class="ulchildlink"><strong><a href="remdta.htm">Remote data areas</a></strong><br />
A remote data area is a data area on a remote server.</li>
<li class="ulchildlink"><strong><a href="crtda.htm">Create a data area</a></strong><br />
Unlike variables, data areas are objects and must be created before they can be used.</li>
<li class="ulchildlink"><strong><a href="dalal.htm">Data area locking and allocation</a></strong><br />
Locking and allocating a data area helps to ensure that the data area is not accessed by more than one job at a time.</li>
<li class="ulchildlink"><strong><a href="disda.htm">Display a data area</a></strong><br />
You can display the attributes (name, library, type, length, data area text description) and the value of a data area.</li>
<li class="ulchildlink"><strong><a href="chgda.htm">Change a data area</a></strong><br />
You can change the value of a data area.</li>
<li class="ulchildlink"><strong><a href="retda.htm">Retrieve a data area</a></strong><br />
You can retrieve a data area and copy it to a variable.</li>
<li class="ulchildlink"><strong><a href="excop.htm">Examples: Retrieve a data area</a></strong><br />
These examples show different ways of retrieving a data area.</li>
<li class="ulchildlink"><strong><a href="crdae.htm">Example: Change and retrieve a data area</a></strong><br />
This example shows how to change and retrieve a data area.</li>
</ul>
<div class="familylinks">
<div class="parentlink"><strong>Parent topic:</strong> <a href="clpgcomm.htm" title="This gives information about how programs and procedures can communicate using data queues and data areas.">Communicate between programs and procedures</a></div>
</div>
<div class="relinfo"><strong>Related information</strong><br />
<div><a href="../cl/crtdtaara.htm">Create Data Area (CRTDTAARA) command</a></div>
<div><a href="../cl/rtvdtaara.htm">Retrieve Data Area (RTVDTAARA) command</a></div>
<div><a href="../cl/chgdtaara.htm">Change Data Area (CHGDTAARA) command</a></div>
<div><a href="../cl/dspdtaara.htm">Display Data Area (DSPDTAARA) command</a></div>
<div><a href="../cl/dltdtaara.htm">Delete Data Area (DLTDTAARA) command</a></div>
<div><a href="../rzaki/rzakikickoff.htm">Journal management</a></div>
</div>
</div>
</body>
</html>