Mind.random()

From Oracle 10g, Dropped tables can be restored. Meaning, you can now rollback one of your DDL statement. This is how you do it.

drop table t;

Table dropped.

desc t;

ERROR: ORA-04043: object t does not exist

select count(*) from t;

select count(*) from t;

ERROR at line 1: ORA-00942: table or view does not exist

flashback table t to before drop;

Flashback complete.

You have now restored your table.

Behind the scenes, what happens is that your dropped table is renamed and just gets restored from the recyle-bin when you “flashback”.

drop table t;

Table dropped.

select table_name from user_tables;

no rows selected

select object_name from recyclebin;

OBJECT_NAME

——————————

BIN$7oTtcup30ZfgMAGK/3hjKw==

flashback table t to before drop;

Flashback complete.

select object_name from recyclebin;

no rows selected

select table_name from user_tables;

TABLE_NAME

——————————

T

So, your table will not really be dropped. But just like any operating system moved to the recycle-bin from which you can restore later.

If you dont want your tables to be restored and be gone forever, then

drop table t purge;

Table dropped.

select table_name from user_tables;

no rows selected

select object_name from recyclebin;

no rows selected

source: Ask Tom