As far as i know sys.dm_db_index_usage_stats should have one record per table and index
No. It has one row for each index which has been used since SQL last started. If an index has not been used in any way since SQL last started, it will have no row in that DMV.
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