Symptoms You don't see what you expect to see. As an example, you get a negative amount for aggregation in an INT type Measures even though it only contains positive values. To explain this I'll take above mention example. Cause This is most likely caused by the capacity insufficiency of INT data type. Resolution Update Measures' data type to BIGINT (Since that will be the next large best datatype for INT ). Into the Depth When the data warehouse fact table contains records like below, Record # Amount Month_Key Year_Key Record 1 500000000 2016/Jan 2016 Record 2 500000000 2016/Feb 2016 Record 3 500000000 2016/Mar 2016 Record 4 1000000000 2016/Apr 2016 Record 5 1000000000 2016/May 2016 Record 6 100000000 2016/Jun 2016 Record 7 500000000 2016/Jul 2016 Querying amount for each month will show positive values The amount for Janu...