Designed and written by highly experienced IMS practicioners, this course teaches how to analyse IMS/DB performance and how to identify potential problems. Attendees will also learn effective tuning techniques that will help them to get the most out of their IMS/DB systems.<br><br>This course is also available 'on demand' (minimum 2 students) for public presentations or for one-company, on-site presentations.


Course attendees should have a sound knowledge of IMS at a conceptual level and knowledge of the IMS environment (both batch & online) along with the IMS utilities, Familiarity with z/OS control programs and VSAM is also assumed.

Delegates will learn how to

  • define a performance strategy
  • identify potential problems
  • understand data sources
  • analyse data
  • predict and evaluate changes.



A superset view of an IMS online system; Course objectives; Online System Structure; A day in the life of a full function message; Stages of Message Processing; Transaction Log records; Addressing IMS Performance Issues; Why Monitor; Establishing monitoring strategies; z/OS System Information; WorkLoad Manager priorities; Workload Manager settings; Monitoring Tools; VSAM LISTCAT output; Data gathering; Batch executions; DL/I Call Image Trace; Exercise 1.

Online Reporting

Log Transaction Analysis Utility (DFSILTA0); Statistical Analysis Utility (DFSISTS0); DC Monitor Reports; Statistic Log Record Analysis; Online Control Region/DFSPBxxx; IMS key performance indicators; IMS Monitor -Output Sequence and Information; Message Queue Pool Report; Message Format Pool Report; Region Summary Report; Region IWAIT Report; Programs by Region Report; Program Summary Report; Events that can be distributed & their default ranges; Program I/O Report; Transaction Queuing Report; DL/I Call Summary report; Deadlock Analysis Report; PI Trace Record; Program to Program switches.

Database Characteristics

Database performance choices; HISAM; HISAM VSAM Logical Record; Insert Root 4; Insert Root 5; Insert Dependents G22 and D24; HIDAM Indexed Access; HD Storage; Free Space Element; Physical Child First Pointers; Physical Twin Pointers; Physical Child Last Pointers; Pointer Options; (P)HIDAM; HDAM Direct Root Access; HDAM Storage; Randomiser Function; Randomiser Algorithm; Sequential Randomiser; HDAM DBD Parameters; The HDAM Variables; The Randomiser; How big is the RAA?; How many RASP; Randomisation Characteristics; What should Bytes be?; How big is SIZE?; HD free space; What about FRSPC?; HD Data Set Crawl; HD space search algorithm; How do you know well it is set up?; Rules of Thumb; DEDB; DEDB Unit Of Work; DEDB Storage; SDep Storage; Standard FP Buffer Pool specifications; Fld Call; Subset Pointers; Locking; High Speed Sequential Processing; OSAM vs VSAM; Database Buffer Pools; HALDB; HALDB Database; Self healing pointers; HALDB Data Sets; HALDB online reorganisation; Database design for performance.

Application Considerations

Application Design for Performance; Activating DFSSTAT; DFSSTAT VSAM Pool Statistics; DFSSTAT OSAM Pool Statistics; DFSSTAT Sequential Buffering Summary; DFSSTAT Sequential Buffering Page A; DFSSTAT Sequential Buffering Page B; DFSSTAT Sequential Buffering Page C; Exercise 2.

Putting the Factors into Practice

Logging Performance Considerations; Access Method Choices; Block, CI and Record Sizes; DB Monitor Reports; VSAM Buffer (Sub)Pool Statistics; VSAM Statistics; OSAM Buffer Pool Statistics; Program I/O Report; DL/I Call Summary Report; Utilities; HISAM Unload Statistics; HISAM Reload Statistics; HISAM Free Space; HD Unload Statistics; HD Reload Statistics; Image Copy and Recovery Optimisation; IMS - DB2 Subsystem Link; Each Dependent Region...Another DB2; Exploiting ODBA from DB2 Stored Procedures; Parallel Sysplex; Locking with IRLM; Shared SDeps; Resources