Slow Drop Schema and Datapump Export Schema in Oracle 11g

ISSUE:
it is very slow to drop a schema or export  the schema in oracle 11g database.

CAUSE:
there are too many objects in the schema. In my case the schema has 1.4 million subpartitions.

SOLUTION:
to Drop the schema:  drop at table level or subpartion level first and then drop the schema.
to EXport the schema: reduce object number by combine partitions or change table definition. Otherwise metadata export will cost too much time to be completed.


reference:
http://www.oaktable.net/content/dropped-tables-hiding-extents-and-slow-dbafreespace-queries