A nonclustered index can be created on a different segment than the data pages. The on segment_name clause specifies a database segment name on which the index is to be created.
create index titleind on titles(title) on seg1
If you use segment_name when creating a clustered index, the table containing the index moves to the segment you specify. See a system administrator or the database owner before creating tables or indexes on segments; certain segments may be reserved for performance reasons.