InfoSphere^® Optim™ Compare for IMS/VSAM/Sequential File Data User Guide

Compare is a relational comparison facility used to compare the data from one set of source tables with another. This facility is unique in providing the ability to analyze multiple tables to identify not only changes to a pair of tables, but more importantly changes to related tables. By analyzing an entire set of data across multiple tables, users can pinpoint exactly where the changes occurred. Depending on your site’s license, the source of the data can be a set of rows that currently resides in a DB2^® or IMS™ database, VSAM or sequential file, or a set of rows extracted previously from the database and stored.

Introduction to Comparing IMS, VSAM and Sequential Files
Compare is a relational comparison facility used to compare the data from one set of source tables with another. This facility is unique in providing the ability to analyze multiple tables to identify not only changes to a pair of tables, but more importantly changes to related tables. By analyzing an entire set of data across multiple tables, users can pinpoint exactly where the changes occurred.
Session Overview
Assume you want to compare two sets of related data--the version before and the version after executing an application in development. This task comprises three basic steps: specify the two sets of source data to be compared, execute the Compare Process, and review the results.
Data Migration
In addition to extracting sets of related data as part of the Compare Process when needed to obtain the source data, Compare enables you to extract the data as a separate, explicit process and store that data in an Extract File. When you extract the data as a separate process, you can compare data from different subsystems.
Compare Process
Compare provides a powerful facility for comparing two sets of related data. This topic details the steps used to perform the Compare Process.
Batch Utility
Most options that may be specified using the online Compare panel are also available using the COMPARE batch processing statement. Use a COMPARE statement to compare two sets of related data. You can compare a set of rows that resides in database tables, VSAM or sequential files, or rows extracted previously and stored in an Extract or Archive File. Results of a comparison are stored in a Compare File or can be used to create a report.
Compare Column Map Compatibility
The Compare rules for Column Maps allow you to map columns with dissimilar names and columns with compatible data types. Compatible data types are determined as described in this topic.
IMS Database Support
The Optim™ Compare facility supports comparing IMS segments. This section describes some features of Optim™ Compare that are included to support IMS databases. Note that some of the features described, such as the Soft Match options, can also be applied to other data sources such as DB2, VSAM, and sequential files.
Comparing hierarchically related data from VSAM or Seq file
One possible use case of Optim™ Compare may be to compare data that has been unloaded from an IMS database into a file. By defining Optim™ Legacy Tables, Primary Keys, and Relationships that map the unloaded data, the Optim™ solution is able to process (extract, compare) the sequential file of unloaded IMS data. However, when the unloaded IMS data contains one or more unkeyed or non-uniquely keyed segments, additional processing of the data must be performed before it can be used properly with the Optim™ Compare facility, as follows.

InfoSphere® Optim™ Compare for IMS/VSAM/Sequential File Data User Guide

InfoSphere^® Optim™ Compare for IMS/VSAM/Sequential File Data User Guide