Alternatives for Dblink in oracle?
A materialized views is not a replacement for a database link. It would likely create a local materialized view using data pulled accross a database link. What you need to do is tune the query that you are using for your materialized view.

Run the query in sqlplus with timing and autotrace turned on. Look for cartesean joins, full table scans and sorts. There are probably some additional indexes or changes to indexes that you can make that will make the query cheaper to run. You want all of the filtering and sorting to happen on the source side of the link so that you are bringing accross as little data as possible.