Table of Contents


  1. Preface
  2. Introduction to PowerExchange
  3. DBMOVER Configuration File
  4. Netport Jobs
  5. PowerExchange Message Logs and Destination Overrides
  6. SMF Statistics Logging and Reporting
  7. PowerExchange Security
  8. Secure Sockets Layer Support
  9. PowerExchange Alternative Network Security
  10. PowerExchange Nonrelational SQL
  11. DTLDESCRIBE Metadata
  12. PowerExchange Globalization
  13. Using the PowerExchange ODBC Drivers
  14. PowerExchange Datatypes and Conversion Matrix
  15. Appendix A: DTL__CAPXTIMESTAMP Time Stamps
  16. Appendix B: PowerExchange Glossary

IMS Considerations

IMS Considerations

The IMS interface modules DTLAMDL1 and DTLAMDBA use GU keyed access if the access supports the values supplied in the WHERE clause for all CCK columns .
The IMS interface modules uses non-optimized GN calls to retrieve records when one of the following is true:
  • The WHERE clause includes unsupported values for CCK columns.
  • The low- and high-rationalized key values differ because the conditions include GE/GT, or LE/LE operands. IMS does not support ranges.
While you can define non-unique search fields in DL/1 and ODBA maps, the read process ignores non-unique search fields when it searches for keys to be used for optimized reading. CCK columns can be reliably used while results are less predictable with other types of non-unique search fields.
For IMS randomized DEDB, HDAM, PHDAM database types, data is physically stored in a randomized sequence. If records must be fetched with unoptimized GN calls, the entire database is read.


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