SQL4029 - Hashing algorithm used to process the grouping

SQL4029
Message Text: Hashing algorithm used to process the grouping
Cause Text: The grouping specified within the query was implemented with a hashing algorithm.
Recovery Text: Implementing the grouping with the hashing algorithm is generally a performance advantage since an index does not have to be created. However, if you want to disallow the use of this method simply specify ALWCPYDTA(*YES).

Refer to Data access on DB2 UDB for iSeries: data access paths and methods for more information about the hashing algorithm.