Oracle Create Materialized View Script - Takes 12 minutes in DEV Schema, 5+ days in QA Schema
Start by focusing on the query used by the materialized view.  Examine why the query is running slow and you will solve why the materialized view creation is running slow.  If this is the case it may require another question on the query itself.  In the unlikely event that the queries run in the same amount of time, let us know.