shrink space

An user complained that querying a table in uat took lot of time compared to production. To resolve the problem, I did the following.

SQL> alter table schemaname.tablename enable row movement
/
Table altered.

SQL> alter table schemaname.tablename shrink space
/
Table altered.


Conditions
-------------------
Make sure that the tablespace has double the size of the table
Make sure that the undo tablespace and temp tablespace have enough space
Avoid using this method if the table has LOB's, etc.