shrink a database in oracle 11g

Question

I am not a database administrator by any means so I might be wrong in stating some of the things here.

In SQL Server, when we add a large amount of data in the database

Answer 1

Full explanation from the Oracle Documentation: Reclaiming Wasted Space. For the short version:

"You can shrink space in a table, index-organized table, index, partition, subpartition, materialized view, or materialized view log. You do this using ALTER TABLE, ALTER INDEX, ALTER MATERIALIZED VIEW, or ALTER MATERIALIZED VIEW LOG statement with the SHRINK SPACE clause."

So, after running the Oracle Segment Advisor to recommend areas to shrink, something like the following will shrink space in a table named mytable.

SQL> alter table mytable enable row movement;
Table altered

SQL> alter table mytable shrink space;
Table altered