Drop table in PL SQL

To move a table to the recycle bin or remove it entirely from the database, you use the DROP TABLE statement:

   DROP TABLE schema_name.table_name
   [CASCADE CONSTRAINTS | PURGE];

First, indicate the table and its schema that you want to drop after the DROP TABLE clause. If you don’t specify the schema name explicitly, the statement assumes that you are removing the table from your own schema.
Second, specify CASCADE CONSTRAINTS clause to remove all referential integrity constraints which refer to primary and unique keys in the table. In case such referential integrity constraints exist and you don’t use this clause, Oracle returns an error and stops removing the table.
Third, specify PURGE clause if you want to drop the table and release the space associated with it at once. By using the PURGE clause, Oracle will not place the table and its dependent objects into the recycle bin.