Chapter 26: Further Reading - IMS Database and Transaction Management

Books

"IMS: A Practical Guide to IMS Database Management" by Hank Fadden A comprehensive treatment of IMS database concepts written for application programmers. This book excels at explaining the hierarchical model in terms that COBOL developers can immediately apply. Chapters on DL/I call processing and segment search arguments are particularly well done, with extensive worked examples that mirror real production scenarios.

"An Introduction to IMS" by Dean H. Meltz, Rick Long, Mark Harrington, Robert Hain, and Geoff Nicholls (IBM Press) This IBM Press title provides a thorough yet accessible overview of IMS from both the database and transaction management perspectives. It is especially valuable for understanding the relationship between IMS DB and IMS TM (DC), and how they work together to support high-volume online transaction processing. The book covers modern IMS features including Open Database and the IMS Connect facility.

"IMS Database Recovery Control (DBRC)" by IBM Redbooks For those who need to understand the operational side of IMS, this Redbook covers database recovery, change accumulation, log management, and the DBRC utility in detail. While primarily aimed at system administrators, the concepts of recovery and restart are critical for COBOL developers who write checkpoint logic in batch DL/I programs.

Online Resources

IBM Developer: IMS Learning Resources and Tutorials IBM's developer portal provides a curated set of IMS tutorials, sample applications, and sandbox environments. The hands-on labs allow COBOL programmers to practice DL/I calls against sample hierarchical databases without needing access to a live mainframe. The tutorials progress from basic retrieval operations to complex path calls with multiple SSAs.

IMS Open Database and RESTful Access Documentation IBM has modernized IMS with open access capabilities that allow IMS databases to be queried via SQL, JDBC, and REST APIs. These resources explain how legacy IMS hierarchical databases can be exposed to modern applications, which is increasingly relevant as enterprises adopt hybrid integration strategies.

Planet Mainframe: IMS Technical Articles and Case Studies This community-maintained portal publishes articles from experienced IMS practitioners covering topics such as database design patterns, performance optimization, and migration strategies. The case studies from banking and insurance organizations illustrate how IMS databases scale to handle millions of transactions per day.

IBM Documentation

"IMS Version 15 Application Programming Guide" (SC19-4830) This is the definitive IBM reference for writing COBOL programs that access IMS databases. It covers every DL/I call in exhaustive detail, with complete syntax diagrams, status code tables, and programming guidelines. The sections on batch message processing (BMP) programs and online MPP programming are essential reading for any IMS application developer.

"IMS Version 15 Database Administration Guide" (SC19-4829) While aimed at database administrators, this manual provides essential background on DBD and PSB generation, access method selection (HISAM, HIDAM, HDAM, HSAM), secondary index creation, and logical relationship definition. COBOL developers benefit from understanding these concepts because the database structure directly influences how DL/I calls must be coded.

"IMS Version 15 Messages and Codes" (GC19-4843) A complete reference for every IMS status code, abend code, and message. When a DL/I call returns an unexpected status code or an IMS program abends, this manual is the first place to look. Each code entry includes the cause, a detailed explanation, and recommended programmer or system action.

Standards and Specifications

"IMS Hierarchical Data Model: Design and Normalization Principles" Academic and industry papers on hierarchical database design provide important theoretical grounding for understanding why IMS databases are structured the way they are. Topics include segment sequencing, twin chain management, and the trade-offs between physical and logical database design. Understanding these principles helps COBOL developers write more efficient DL/I navigation logic.

COBOL DL/I Interface Standards and Conventions (IBM Enterprise COBOL) IBM Enterprise COBOL for z/OS includes specific documentation on the COBOL-to-DL/I interface, covering the ENTRY statement for BMP/MPP programs, the GOBACK convention, PCB list processing in the LINKAGE SECTION, and the CBLTDLI versus AIBTDLI call formats. This reference bridges the gap between IMS database concepts and their concrete implementation in COBOL source code.