I'm buildind an data warehouse. Each fact has it's timestamp. I need to create reports by day, month, quater but by hours too. Loking at the examples I see that dates tend to be saved in dimension tabels.

But I think, that it makes no sense for time. The dimension table would grow and grow. On the other hand JOIN with date dimension table is more efficent than using date/time functions in SQL.

What are your opinions/solutions ?

(I'm using Infobright)