Flashback Drop - restoring a dropped table from the Recycle Bin

Let's say we have dropped a table by mistake and we need to restore it.

Can we restore the table with RMAN backup?  Yes, we can. But we got a lot of works to do. We restore the data file(tablespace) that contains the dropped table or the whole database to a new host from the backup. And then we can export and import the table from the database restored in the new host to the target database. Both the tablespace/database restoring process and the export/import process require a lot of detailed steps.

Do we have a quicker way? We can just use Flashback technology to restore the dropped table quickly. "Flashback Drop" allows us to restore a dropped table from the Recycle Bin as long as the table has not been purged yet.

When we drop a table, the table and all associated objects(indexes, contraints) are renamed as "BIN$..."  They still exists in the database and still belongs to the owner. They are just remapped to the recycle bin. Because of this reason, we can simply restore the dropped table.     
           SQL> FLASHBACK TABLE table_name TO BEFORE DROP;

When the table is restored, the associated objects and contraints are also restored except for the referential integrity contraints and bitmap indexes.  Note that the name of the restored associated objects and contraints, however, still remains as "BIN$..."  Not reverted back to their original name. It is the DBA's job to rename the restored objects and contraints if needed.

In order to be able to use Flashback DROP feature, we first have to make sure that RECYCLEBIN initialization parameter is set to 'ON' (default). Lastly, be aware that Oracle automatically reclaim space in the recycle bin when additional space is needed by purging the oldest dropped object in the recyle bin (FIFO basis). Once an object is purged, that object no longer exists in the database. As a result, we cannot restore the object from the recycle bin with FLASHBACK DROP.