Data File Comparison  A Self-Study or Classroom Session

Introduction
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The session will describe how to compare two data files that reside on a Windows (or UNIX) platform using Micro Focus COBOL and Micro Focus file formats. An exercise in the form of a sample Proof-of-Concept (POC) is provided that will use SimoTime technologies to generate the COBOL source code that may be compiled and executed using Micro Focus COBOL. Since the generated COBOL source code is COBOL/2 compliant it may be compiled and executed on a mainframe (either z/OS or VSE) to compare VSAM or QSAM files. For this exercise only the Windows operating system with Micro Focus COBOL will be used.

To perform this exercise requires a basic knowledge of the Windows environment and Micro Focus Net Express. Additional help is provided for individuals that may not be proficient in the use of Net Express or have forgotten how to perform a particular function.

Objective of Session
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The objective of this session is to define a practical process for comparing two data files on a Windows platform using Micro Focus Net Express. The following is a list of the minimum tasks to be completed for this Session.

Requirements
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If this session is being performed through self-study then it will be necessary to install the following software on a Windows system. Windows/XP or Windows Server is preferred.

Materials Provided
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For the classroom environment two directories (c:\DataMig1 and c:\SimoLIBR) are provided that contain the following information.

Criteria for Success
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The following items must be completed to meet the minimum requirements for successfully completing the proof of concept.

What to do and How to do it
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The objective of this project is to experience first-hand the issues that will be encountered and the solutions required when doing data file comparisons on a Windows platform. Because most mainframe files contain a mixture of alpha-numeric fields (i.e. "USAGE IS DISPLAY" in COBOL terminology) and numeric fields that may be packed (COMP-3) or binary (COMP) the data file comparison process will need to handle this format and properly display differences in a format that is easily understood by human beings.

For this project two directories will be used. The first directory (c:\SimoLIBR) contains the utility programs and copy files needed to generate the COBOL data file comparison program. The c:\SimoLIBR directory will need to be included in the PATH environment variable. The second directory (c:\DataMig1) contains the modules and data files specific to this learning session.

The following sections describe a series of tasks that must be accomplished to successfully complete this learning session.

Step-01, Data File Compare, Generate Source Code
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Generate the COBOL source member for a Data File Comparison program.

Refer to the document for Data File Compare, Generate Source Code for additional help.

Note:  If this procedure does not run correctly the problem is usually with the c:\SimoLIBR directory. Either the SimoZAPS or SimoREC1 utility programs were not installed correctly or the c:\SimoLIBR directory is not in the PATH.

Step-02, Create HTML Documentation for Copy File
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Create HTML Documentation based on a COBOL copy. This documentation will be used as reference material when a difference occurs during the compare process. This documentation is generated based on the information (or record layout) as defined in a COBOL copy file.

Refer to the Creating HTML Documentation for additional information.

Step-03, Data File Compare, View Source Code
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Verify that a COBOL source member was created (ItCompC1.CBL) and placed in the c:\DataMig1\COBOL directory.

Verify that an HTML document was created (itemcb01.htm) and placed in the c:\DataMig1\HTML directory.

Refer to the document for Data File Compare, View Source Code for additional help.

Note:  If step 1 is successful then the COBOL source member should be automatically displayed with NotePAD. You may view the source code and then close the NotePAD windows. Do not change the source code.

Step-04, Data File Compare, Compile Generated Source Code
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Compile the generated COBOL source member as a DLL using the command line interface for Micro Focus Net Express.

Refer to the Net Express Command Line Interface document for additional information about compiling a COBOL source member and creating a Load member.

Step-05, Execute Data File Compare
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Execute the data file compare program and examine the differences.

For help in executing the program refer to the Execute the Data File Compare Program and Examine the Differences document for additional information. This document also describes how to map data file names.

Additional Information
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This section provides additional information or insight into some of the tasks performed by this exercise. There are numerous things to consider when comparing data files. The comparison task is easy, in today's environment with possible ASCII or EBCDIC encoded files along with packed or binary numeric fields within a record it becomes a challenge as to how to properly display and interpret this information when a difference occurs.

Numeric Fields, BINARY or COMP Format
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This link provides additional information about Binary or COMP (i.e. COMPUTATIONAL) fields

    Explore The Binary or COMP format for numeric data strings. This numeric structure is supported by COBOL and may be explicitly defined with the "USAGE IS COMP" or "USAGE IS BINARY" clause.

Numeric Fields, Packed-Decimal or COMP-3 Format
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This link provides additional information about Packed Decimal or COMP-3 (i.e. COMPUTATIONAL-3) fields.

    Explore The Packed-Decimal or COMP-3 format for numeric data strings. This numeric structure is supported by COBOL and may be explicitly defined with the "USAGE IS COMP-3" clause.

Numeric Fields, Zone Decimal Format
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This link provides additional information about Zone Decimal fields. The unsigned, zone decimal fields are text fields and are assumed to be a simple, no risk conversion. However, it is best to treat unsigned fields as signed since it is possible for a signed zone value to end up in an unsigned field and as long as it is a positive value the mainframe will process the field.

Signed fields that are in a zone decimal format need special handling and should not be handled as text data.

    Explore The Zoned-Decimal format for numeric data strings. This numeric structure is the default numeric for COBOL and may be explicitly defined with the "USAGE IS DISPLAY" clause.

Summary
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The purpose of this session is to describe the techniques and effort involved to compare two data file on a Windows platform using Micro Focus COBOL and Micro Focus formatted files. This session is available as an on site class or an on line, self-study course.

Software Agreement and Disclaimer
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Permission to use, copy, modify and distribute this software, documentation or training material for any purpose requires a fee to be paid to SimoTime Enterprises. Once the fee is received by SimoTime the latest version of the software, documentation or training material will be delivered and a license will be granted for use within an enterprise, provided the SimoTime copyright notice appear on all copies of the software. The SimoTime name or Logo may not be used in any advertising or publicity pertaining to the use of the software without the written permission of SimoTime Enterprises.

SimoTime Enterprises makes no warranty or representations about the suitability of the software, documentation or learning material for any purpose. It is provided "AS IS" without any expressed or implied warranty, including the implied warranties of merchantability, fitness for a particular purpose and non-infringement. SimoTime Enterprises shall not be liable for any direct, indirect, special or consequential damages resulting from the loss of use, data or projects, whether in an action of contract or tort, arising out of or in connection with the use or performance of this software, documentation or training material.

Downloads and Links to Similar Pages
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This section includes links to documents with additional information that are beyond the scope and purpose of this document.

Note: The latest versions of the SimoTime Documents and Program Suites are available on the Internet and may be accessed using the icon. If a user has a SimoTime Enterprise License the Documents and Program Suites may be available on a local server and accessed using the icon.

    Explore The SimoPATH Series starting at the home page to view information about training sessions and learning materials available from SimoTime Enterprises.

    Explore the Principles of Data File Comparison. This link includes guidelines for defining requirements and determining the scope of effort for a data comparison effort.

    Explore How to Generate a Data File Compare Program using simple specification statements in a Process Control File. This link to the User Guide includes the information necessary to create a Process Control File and generate the COBOL programs that will do the actual data file comparison.

    Explore the capabilities of the SimoZAPS Utility Program. This includes generating a COBOL program that will do the conversion of sequential and VSAM (KSDS) files between EBCDIC and ASCII while maintaining mainframe (or COBOL) numeric formats and integrity. SimoZAPS can also read a sequential file in EBCDIC format and create an ASCII/CRLF file or VSAM KSDS file in ASCII format. The conversion tables may be viewed or modified to meet unique requirements. The Hexcess/2 function provides the capability of viewing, finding or patching the contents of a file in hexadecimal.

    Explore How to Document Record Layouts or other Data Structures using a COBOL copy file. For reference or documentation purposes SimoREC1 creates an ASCII/Text file and an HTML document from a COBOL copy file. The utility provides the length of a field and the position of the start of the field within a record. Also, the actual physical length for group items, packed fields, binary fields and tables will be calculated.

    Explore The ASCII and EBCDIC Translation Tables. These tables are provided for individuals that need to better understand the bit structures and differences of the encoding formats.

    Explore The File Status Return Codes to interpret the results of accessing VSAM data sets and/or QSAM files.

    Explore The Binary or COMP format for numeric data strings. This numeric structure is supported by COBOL and may be explicitly defined with the "USAGE IS COMP" or "USAGE IS BINARY" clause.

    Explore The Edited for Display format for numeric data strings. This numeric structure is supported by COBOL and may be used with an edit-mask to prepare the presentation for readability by human beings.

    Explore The Packed-Decimal or COMP-3 format for numeric data strings. This numeric structure is supported by COBOL and may be explicitly defined with the "USAGE IS COMP-3" clause.

    Explore The Zoned-Decimal format for numeric data strings. This numeric structure is the default numeric for COBOL and may be explicitly defined with the "USAGE IS DISPLAY" clause.

    Explore commonly used formats and processing techniques for managing various numeric formats available on the mainframe.

    Explore the Numbers Connection for additional information about the structure and processing of numeric data items (or numeric fields).

    Explore the Hexadecimal Dump capabilites using COBOL to dump the content of a data string. This suite of programs includes a sample program that calls the SIMODUMP program to do the actual formatting for the hexadecimal dump information.

Downloads and Links, Internet Access Required
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The following links will require an internet connect.

A good place to start is The SimoTime Home Page via Internet Connect for access to white papers, program examples and product information.

Explore The Micro Focus Web Site via Internet Connect for more information about products and services available from Micro Focus.

Glossary of Terms
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    Explore the Glossary of Terms for a list of terms and definitions used in this suite of documents and white papers.

Comments, Suggestions or Feedback
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This document was created and is copyrighted and maintained by SimoTime Enterprises.

If you have any questions, suggestions, comments or feedback please call or send an e-mail to: helpdesk@simotime.com

We appreciate hearing from you.

Company Overview
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Founded in 1987, SimoTime Enterprises is a privately owned company. We specialize in the creation and deployment of business applications using new or existing technologies and services. We have a team of individuals that understand the broad range of technologies being used in today's environments. This includes the smallest thin client using the Internet and the very large mainframe systems. There is more to making the Internet work for your company's business than just having a nice looking WEB site. It is about combining the latest technologies and existing technologies with practical business experience. It's about the business of doing business and looking good in the process. Quite often, to reach larger markets or provide a higher level of service to existing customers it requires the newer Internet technologies to work in a complementary manner with existing corporate mainframe systems.

Whether you want to use the Internet to expand into new market segments or as a delivery vehicle for existing business functions simply give us a call or check the web site at http://www.simotime.com