When PowerExchange executed SQL with a WHERE clause against data for Adabas, Datacom, IDMS, IMS or KSDS, the NRDB optimized read process discarded a condition .The condition is still used for post-read qualification. PowerExchange cannot produce limit low and high values for field types from conditions with NOT EQUA:L ( != or <>) syntax.
Processing continues, but the skipped condition causes too many records to be read, which causes slower overall processing.
If possible, construct the SQL WHERE clause condition by using not-less-than (>=) and not-greater-than (<=) comparisons to define the range of records for the optimized read process. This message can be suppressed using the REPORT_UNUSED_OPT_READING_CONDITIONS=N parameter.