Index traversal forbidding the use of Partitions - topic by mjasrotia

I have a 8 billion record Shipments table which is joined to couple other tables. The Shipments tables has some indexes defined and those index columns are being used as filters in my query. The Shipments table is also partitioned on SHIPMENT_DT.   When executing the query Explain plan shows Index Traversal but hitting all the partitions of the Shipments Table which is slowing down the query. Is it a rule or something that when Indexes are used then the Parttitions are not used ?   Please advise   Thanks Manik