How much disk space is required for Oracle Data Pump?

Question
How can I determine how much disk space is needed for using Oracle Data Pump export?

Answer
Run check
expdp $ALEPH_ADMIN ESTIMATE_ONLY=y full=y

Additional Information

1. Please make sure, that ALEPH_ADMIN has the relevant permissions to execute java:

s+ ALEPH_ADMIN
grant JAVA_ADMIN to aleph_admin WITH ADMIN OPTION;

2. Take a note that full=y is not working in Oracle 11.

You might alternately run the following check for each of the libraries:

expdp <bib>/<bib> ESTIMATE_ONLY=y NOLOGFILE=y

Example
expdp abc01/abc01 ESTIMATE_ONLY=y NOLOGFILE=y