We have a data warehouse built in MSSQL 2012, Staging area, EDW, cubes and reports.
In the staging area, the tables are a 1:1 copy of those supporting the systems used to fill the DWH with. The staging area tables are TRUNC'ed and refilled daily (nightly). Then views on those tables provides input for the ETL process towards the EDW.
Besides providing a copy for the EDW to work with, these staging tables are also queried using MSSQL Management Studio by some of our analists, as not to put pressure on the source systems with their queries.
For both the ETL towards EDW as for the analist's queries, I get the idea that having an index on (some of) these tables might aid performance (greatly). Is it wise to have indexes on (large) tables that get TRUNC'ed daily. If not, why? And what kind of index (Clustered vs Non-clusterd vs someting else entirely)?