IBM Information Management System
The Information Management System (IMS) is a database and transaction system.
It has been developed by IBM since 1968 when it was introduced under the name "Control System and Data Language/Interface" (ICS/DL/I), but was renamed IMS the year after. IMS resembles the old DBMS more than the more modern DB2 product in that it follows the hierarchical database model rather than the relational database model that most modern database models follow, however IMS uses multiple hierarchies for each sets of data which is unusual and the Raima Database possibly the only other product to offer such functionality in a modern setting.
IMS is effectively split into three parts, a "queued system" that receives all data and buffers it until it can be processed further, a "transactional system" that organises data and commands into workloads and verifies that each one is finished properly and a "database system" that organises data into hierarchies. The strengths of the IMS system primarily lie in the industrial strength transaction system but it not only makes the system fairly optimised but also by ensuring that all transactions are completed and in the correct order it offers a degree of robustness that is one of the reasons that financial institutions find it difficult to move off the system, and the same can be said about CICS and TPF.
In the latter half of the 80s and the early 90s IBM talked about IMS as a "legacy" product and it was widely believed that its functions would be replaced by a more modern relational database system, especially after the successful introduction of AS/400 and OS/2 1.3 Extended Edition, but both products featured a SQL database system as a base component. However a relational database product offering the same quality of transaction processing has never shown up from any company and this actually lead to IMS sales increasing rather than decreasing around the turn of the century much to industry analysts surprise, and the use of any combination of the word "legacy" and the acronym IMS in the modern IBM is likely to get you fired.
This is any OS/2 product that can either interact with or be used to develop software for an IMS system, given the age of some of those solutions they may not offer any worthwhile functionality in a modern setting.
- VisualAge TeamConnection - Recognises, analyses and sorts IMS code - Commercial
- IBM IMS Homepage
- Uri Berman: The Birth of IMS/360
- IBM 100: Information Management System - Background to the IMS from the horses mouth.
- Closed source commercial software