Although I usually cover DB2 in this column, we’ll take a short break this issue. The purpose of this column is to examine data management issues on IBM’s zSeries platform and DB2 is not the only game in town. So, let’s check on the status of IMS, IBM’s other mainframe DBMS.

IBM celebrated the 35th anniversary of IMS last year— which, in this industry, is a very long time for a software product to thrive. Even more amazing is that IMS continues to grow. In the past two years, IMS has experienced a 55 percent growth in terms of MIPS, as well as a new version (V8) with a lot of new functionality and the announcement of yet another new version (V9) on the horizon. You can connect to IMS databases from just about anywhere these days, due to the robust connectivity offered by IMS Connect and the Open Transaction Management Access (OTMA) facility.

While hierarchical database systems have been surpassed in the marketplace by relational products such as DB2, IMS can brag about its long and proud legacy that continues today. According to IBM, more corporate data is managed by IMS than any other DBMS. IMS manages more than 15 million gigabytes of production data. And more than 95 percent of the companies in the Fortune 1000 use IMS.

In terms of transactions managed, IMS is even more impressive. IBM claims that more than 50 billion transactions are run through IMS daily. Additionally, close to 200 million users a day are served by IMS.

Why does IMS continue to enjoy such success when relational products are more mainstream and easier to use?

One reason is speed. One high-end IMS customer handles 120 million transactions a day; 7 million in a single hour! Another benchmark shows IMS serving 6,000 transactions per second across TCP/IP to a single IMS; impressive numbers, indeed.

Modern application development approaches can be used with IMS, too. The IMS Open Database Access facility (ODBA) provides a callable interface for easier database access. And, as of V7, IMS adds Java support and tools to simplify Java development with IMS. Today, IMS developers can:

  • Use the IMS Client for Java to write Java applets or applications that access IMS transactions
  • Use the IMS Web Studio tool to build end-to-end solutions for accessing IMS transactions from the Internet
  • Use the Java-based IMS Object Connector Class Definition Tool to generate data objects for use by IMS Object application programs
  • Use the class libraries and JavaBeans of the IMS Connector for Java to develop Java applications that access IMS.

IMS Java Remote Database Services in IMS V9 provides Java application programs distributed access to IMS databases. That means your non-z/OS programs will be able to access IMS data over the Internet using a secure protocol with local or global transaction semantics and a standard API.

And, if you haven’t created an IMS database in awhile, you might be in for some surprises. HALDB, a new format introduced with IMS V7, allows database partitioning–and you can grow up to 10,010 data sets per database, resulting in a database size of more than 40TB. HALDB databases also help address some of the pesky management and administration problems that have plagued IMS for years. With self-healing pointers, reorganizing a partition doesn’t require changes to secondary indexes or logically-related databases. HALDB also does away with Prefix Resolution, Prefix Update, and secondary index rebuilds.

IMS also participates in the 24x7, e-business world. Using a combination of IMS and third-party tools, organizations of every type are enabling access to business-critical IMS data round-the-clock over the Web. The next time you make a flight reservation, access your frequent flyer miles, or track a shipment over the Web, you probably have IMS to thank for that service.

Finally, IMS databases are getting easier to manage. IBM’s autonomic computing initiative delivers some self-management features to IMS. Combine these features with third-party tools that improve availability and simplify reorganization, compress IMS data to reduce storage needs, automate and coordinate changes of system definition elements while transactions remain online, and speed up and simplify backup and recovery of IMS databases, and you have a very robust enterprise data management environment.


Truly, there’s no need to worry about having to convert your IMS databases to another DBMS. IBM continues to enhance IMS with the features it needs to continue to support your business. Yes, IMS may be old, but it has evolved over the years to support the needs of modern databases and applications. And just because something is old, doesn’t make it obsolete. I can personally vouch for that!