What privileges are needed to run EXPLAIN PLAN FOR CREATE INDEX?

My user can EXPLAIN PLAN FOR any query I like, but not for CREATE INDEX. I need to do that in order to estimate a suggested index’s size, and using sysdba is out of question. What privileges should I ask for? This is Oracle 11.2.0.3.

SQL> explain plan for create index INDEXNAME on SOMEONE.SOMETABLE("FLD1","FLD2");
explain plan for create index INDEXNAME on SOMEONE.SOMETABLE("FLD1","FLD2")
                                                   *
ERROR at line 1:
ORA-01031: insufficient privileges

SQL> explain plan for select * from SOMEONE.SOMETABLE order by fld1 desc;

Explained.

SQL>

The problem is most likely in you not having sufficient privileges to create the index in question — nothing to do with EXPLAIN PLAN itself.

To quote the manual, “To create an index in another schema, you must have the CREATE ANY INDEX system privilege”.