ORA-56907
string: Duplicate column names are generated due to pivot values being too long or due to the absence of unique and short aliases for both pivot values and aggregates.
Cause
Encountering either duplicate pivot values without unique aliases, multiple aggregates without unique aliases, or a pivot value that is too long. Truncating the pivot value to a specific maximum length can result in duplicate column names.
Action
Assign unique and short aliases to the pivot values and aggregates.