Secondary Index for IMS Modernization Guide

Secondary Index for IMS automatically builds and maintains secondary indexes for IMS DEDB databases. It uses the Index Extractor and Index Builder to create and rebuild indexes offline, minimizing application impact.

The core components are the Index Extractor, which reads the database and extracts index data; the Index Builder, which creates the index structures; and the Secondary Index Call Interceptor, which intercepts DL/I calls.

The Secondary Index Call Interceptor intercepts DL/I calls from applications. It determines if secondary index processing is required based on the call parameters and the index definitions.

Configuration files define the index structure, source database, and processing parameters. These files are used by the Index Extractor and Index Builder to create and maintain the indexes.

The Index Extractor and Index Builder are typically invoked via JCL (Job Control Language) on z/OS. These jobs specify the input data sets, control cards, and execution parameters.

The Secondary Index Call Interceptor is link-edited with each IMS application. This allows it to intercept DL/I calls without requiring application changes.

The product uses standard DL/I calls for interacting with IMS databases. There are no custom APIs exposed.

The Index Extractor and Index Builder operate offline, reading the IMS database sequentially and building the index structures. The Secondary Index Call Interceptor operates in real-time, intercepting DL/I calls.

By automatically maintaining secondary indexes, the product improves application performance by optimizing data retrieval. This reduces the need for full database scans, leading to faster response times.

The product reduces the need for manual index maintenance, freeing up database administrators to focus on other tasks. This automation streamlines operations and reduces operational costs.

The product's ability to create and maintain indexes without application changes reduces the risk associated with application modifications. This simplifies the implementation process and minimizes disruption.

The product leverages the security features of z/OS and IMS. Access to the underlying data is controlled by IMS security mechanisms.

The product does not introduce new authentication mechanisms. It relies on the existing IMS authentication methods.

The product does not perform encryption. Data is stored and transmitted using the existing IMS encryption settings.

The product logs index creation and maintenance activities. These logs can be used for auditing purposes.

The Index Extractor and Index Builder are managed through JCL. Monitoring involves tracking the execution of these jobs and reviewing the associated logs.

The Secondary Index Call Interceptor operates within the IMS environment. Monitoring involves tracking IMS transaction performance and reviewing IMS logs.

Configuration parameters are defined in the configuration files used by the Index Extractor and Index Builder. These parameters control the index structure, source database, and processing options.

User management is handled through the existing IMS security mechanisms. The product does not introduce new user management features.