Please read storage clause description in SQL Reference http://docs.oracle.com/cd/E11882_01/server.112/e26088/clauses009.htm.
It also says:
The specification of storage parameters for objects in locally managed tablespaces is supported for backward compatibility. If you are using locally managed tablespaces, then you can omit these storage parameter when creating objects in those tablespaces.
Edited by: P. Forstmann on 23 mai 2013 19:55
Unless you need to specify something other than default, you do not need a storage clause.
Below is an example of an index storage clause on 11.2, (plus the tablespace since our indexes are in a separate tablespace).