Use USE_MERGE Hint (-nojoinhint) to override USE_MERGE default query-tuning hint for OUTER-JOIN query.

Operating system and syntax UNIX / Windows -nojoinhint
Use with Maximum value Minimum value Single-user default Multi-user default
DataServer — — — —

USE_MERGE proves to be a costly affair when a few records are needed out of the large join result set. In this case, ABL application can turn-off USE_MERGE hint by compiling application with -nojoinhint client startup parameter which may result in better performance. The -nojoinhint is to be used at compile time only. It has no impact on run time. This parameter is valid only when using the DataServer for Oracle.