Designing a data mart for a messaging application. End users want to be able to display a histogram with the ability to show message volume in 5, 10, 15, 20, 25, 30, 1 hr intervals. In this case, would you populate the Time dimension with date/time data in 5-min. intervals. So each hour would be 12 records in the time dim. This results in approx. 105,120 rows per Year. I'm thinking of keeping the granularity to a Day in the time dimension, and just using an attribute in the fact table to note the time in the 5-minute increment.