Sorts are expensive operations and distinct requires a sort, as do most other methods of removing duplicates from a resuuklt set.
The best 'workaround' is to find out why there are duplicated (bad data, bad database design, bad query) and fix that. If you don't need distinct, don't use it.
Gail Shaw
Microsoft Certified Master: SQL Server, MVP, M.Sc (Comp Sci)
SQL In The Wild: Discussions on DB performance with occasional diversions into recoverability