When PowerExchange executed SQL with a WHERE clause against data for Adabas, Datacom, IDMS, IMS or KSDS, the NRDB optimized reading process discarded a condition .The condition is still used for post-read qualification. PowerExchange cannot produce limit low and high values for field types that do not have defined rules, such as the following types:
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 using comparisons on fields that are used in a database key. Database keys do not typically contain fields with variable lengths. This message can be suppressed using the REPORT_UNUSED_OPT_READING_CONDITIONS=N parameter.