126 lines
7.6 KiB
HTML
126 lines
7.6 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="concept" />
|
||
|
|
<meta name="DC.Title" content="Define logical file members" />
|
||
|
|
<meta name="abstract" content="You can define members in logical files to separate the data into logical groups. The logical file member can be associated with one or several physical file members." />
|
||
|
|
<meta name="description" content="You can define members in logical files to separate the data into logical groups. The logical file member can be associated with one or several physical file members." />
|
||
|
|
<meta name="DC.subject" content="logical file member, member, logical file" />
|
||
|
|
<meta name="keywords" content="logical file member, member, logical file" />
|
||
|
|
<meta name="DC.Relation" scheme="URI" content="rbafocrlof.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="rbafologfm" />
|
||
|
|
<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>Define logical file members</title>
|
||
|
|
</head>
|
||
|
|
<body id="rbafologfm"><a name="rbafologfm"><!-- --></a>
|
||
|
|
<!-- Java sync-link --><script language="Javascript" src="../rzahg/synch.js" type="text/javascript"></script>
|
||
|
|
<h1 class="topictitle1">Define logical file members</h1>
|
||
|
|
<div><p>You can define members in logical files to separate the data into
|
||
|
|
logical groups. The logical file member can be associated with one or several
|
||
|
|
physical file members.</p>
|
||
|
|
<p>The following chart illustrates this concept:</p>
|
||
|
|
<br /><img src="rbafo506.gif" alt="Logical file members" /><br /><p>The record formats used with all logical members in a logical file must
|
||
|
|
be defined in data description specifications (DDS) when the file is created.
|
||
|
|
If new record formats are needed, another logical file or record format must
|
||
|
|
be created.</p>
|
||
|
|
<p>The attributes
|
||
|
|
of an access path are determined by the information specified in DDS and on
|
||
|
|
commands when the logical file is created. The selection of data members is
|
||
|
|
specified in the DTAMBRS parameter on the Create Logical File (CRTLF) and
|
||
|
|
Add Logical File Member (ADDLFM) commands.</p>
|
||
|
|
<p>When a logical file is defined, the physical files used by the logical
|
||
|
|
file are specified in DDS by the record-level PFILE or JFILE
|
||
|
|
keyword. If multiple record formats are defined in DDS, a PFILE keyword must
|
||
|
|
be specified for each record format. You can specify one or more physical
|
||
|
|
files for each PFILE keyword.</p>
|
||
|
|
<p>When a logical file is created
|
||
|
|
or a member is added to the file, you can use the DTAMBRS parameter on the
|
||
|
|
CRTLF or the ADDLFM command to specify which members of the physical files
|
||
|
|
used by the logical file are to be used for data. *NONE can be specified as
|
||
|
|
the physical file member name if no members from a physical file are to be
|
||
|
|
used for data.</p>
|
||
|
|
<p>In the following example, the logical file has two record formats defined:</p>
|
||
|
|
<pre>|...+....1....+....2....+....3....+....4....+....5....+....6....+....7....+....8
|
||
|
|
A
|
||
|
|
00010A R LOGRCD2 PFILE(PF1 PF2)
|
||
|
|
A .
|
||
|
|
A .
|
||
|
|
A .
|
||
|
|
00020A R LOGRCD3 PFILE(PF1 PF2 PF3)
|
||
|
|
A .
|
||
|
|
A .
|
||
|
|
A .
|
||
|
|
A</pre>
|
||
|
|
<div class="p">If the DTAMBRS parameter is specified on the CRTLF or ADDLFM command as
|
||
|
|
in the following example: <pre>DTAMBRS((PF1 M1) (PF2 (M1 M2)) (PF1 M1) (PF2 (*NONE)) (PF3 M3))</pre>
|
||
|
|
</div>
|
||
|
|
<p>Record format LOGRCD2 is associated with physical file member M1 in PF1
|
||
|
|
and M1 and M2 in file PF2. Record format LOGRCD3 is associated with M1 in
|
||
|
|
PF1 and M3 in PF3. No members in PF2 are associated with LOGRCD3. If the same
|
||
|
|
physical file name is specified on more than one PFILE keyword, each occurrence
|
||
|
|
of the physical file name is handled as a different physical file.</p>
|
||
|
|
<p>If a library name is not specified for the file on the PFILE keyword, the
|
||
|
|
library list is used to find the physical file when the logical file is created.
|
||
|
|
The physical file name and the library name then become part of the logical
|
||
|
|
file description. The physical file names and the library names specified
|
||
|
|
on the DTAMBRS parameter must be the same as those stored in the logical file
|
||
|
|
description.</p>
|
||
|
|
<p>If a file name is not qualified by a library name on the DTAMBRS parameter,
|
||
|
|
the library name defaults to *CURRENT, and the system uses the library name
|
||
|
|
that is stored in the logical file description for the respective physical
|
||
|
|
file name. This library name is either the library name that was specified
|
||
|
|
for the file on the PFILE DDS keyword or the name of the library in which
|
||
|
|
the file was found using the library list when the logical file was created.</p>
|
||
|
|
<div class="p">When you add a member to a logical file, you can specify data members as
|
||
|
|
follows: <ul><li>Specify no associated physical file members (DTAMBRS (*ALL) default).
|
||
|
|
The logical file member is associated with all the physical file members of
|
||
|
|
all physical files in all the PFILE keywords specified in the logical file
|
||
|
|
DDS.</li>
|
||
|
|
<li>Specify the associated physical file members (DTAMBRS parameter). If you
|
||
|
|
do not specify library names, the logical file determines the libraries used.
|
||
|
|
When more than one physical file member is specified for a physical file,
|
||
|
|
the member names should be specified in the order in which records are to
|
||
|
|
be retrieved when duplicate key values occur across those members. If you
|
||
|
|
do not want to include any members from a particular physical file, either
|
||
|
|
do not specify the physical file name or specify the physical file name and
|
||
|
|
*NONE for the member name. This method can be used to define a logical file
|
||
|
|
member that contains a subset of the record formats defined for the logical
|
||
|
|
file.</li>
|
||
|
|
</ul>
|
||
|
|
</div>
|
||
|
|
<div class="p">You can use the Create Logical File (CRTLF) command to create the first
|
||
|
|
member when you create the logical file. Subsequent members must be added
|
||
|
|
using the Add Logical File Member (ADDLFM) command. However, if you are going
|
||
|
|
to add more members, you must specify more than 1 for the MAXMBRS parameter
|
||
|
|
on the CRTLF command. The following example of adding a member to a logical
|
||
|
|
file uses the CRTLF command. <pre>CRTLF FILE(DSTPRODLB/ORDHDRL)
|
||
|
|
MBR(*FILE) DTAMBRS(*ALL)
|
||
|
|
TEXT('Order header logical file')</pre>
|
||
|
|
</div>
|
||
|
|
<p>*FILE is the default for the MBR parameter and means that the name of the
|
||
|
|
member is the same as the name of the file. All the members of the associated
|
||
|
|
physical file (ORDHDRP) are used in the logical file (ORDHDRL) member. The
|
||
|
|
text description is the text description of the member.</p>
|
||
|
|
</div>
|
||
|
|
<div>
|
||
|
|
<div class="familylinks">
|
||
|
|
<div class="parentlink"><strong>Parent topic:</strong> <a href="rbafocrlof.htm" title="This topic shows how to create a logical file using data description specifications (DDS).">Create a logical file</a></div>
|
||
|
|
</div>
|
||
|
|
</div>
|
||
|
|
</body>
|
||
|
|
</html>
|