ORA-14312
Duplicate key specified: a value of string already exists in partition string.
Cause
One of the literal values in the ALTER TABLE ... ADD PARTITION or ALTER TABLE ... ADD VALUES clause already exists in another list partition or list sub-partition.
Action
Remove the duplicate value from the statement and try again. If you are unsure which values have been specified in the current schema's list-partitions, you can find more information in the following data dictionary views:
- USER_TAB_PARTITIONS
- USER_TAB_SUBPARTITIONS