In Oracle 10G a table is not truly dropped by using the drop table command. It is only renamed and considered inside Oracle’s recycle bin. This is important to know for 2 reasons.
1. If you drop a table it still counts against your tablespace until you remove it from the recycle bin.
2. If you change your mind about dropping a table you can simply flashback the table and the table structure with the data will be back.
To retrieve a table you dropped consider the following.
flashback table t to before drop;
To remove a table from the recycle bin after it’s been dropped
delete from recyclebin where original_name = 't';
To drop a table and skip the recycle bin
drop table t purge;