ORA-02449 Error Code Description:

Error	ORA-02449
Description	unique/primary keys in table referenced by foreign keys
Cause	An attempt was made to drop a table with unique or primary keys referenced by foreign keys in another table.
Action	Before performing the above operations the table, drop the foreign key constraints in other tables. You can see what constraints are referencing a table by issuing the following command: SELECT * FROM USER_CONSTRAINTS WHERE TABLE_NAME = "tabnam";