To build OLAP cubes in Oracle 9i DB in Windows 2000 Server following
are my questions:-

Is most appropriate tool for building and maintaining cubes and
dimensions is Oracle
Express Server?
Does Express server get installed with Oracle 9i DB installation, by
default? From where I can use it?
What tools, other than Reports Developer and Discoverer, I may use on
client side to build OLAP based reports?