[Chad Wagner - Tue at 08:24:34AM -0500] > I guess go with your gut, but at some point the expressions are going to be > too complicated to maintain, and inefficient. The layout of my system is quite flexible, so it should eventually be fairly trivial to throw in a date dimension at a later stage. > Calendar tables are very very common, because traditional date functions > simply can't define business logic (especially things like month end close, > quarter end close, and year end close) that doesn't have any repeating > patterns (every 4th friday, 1st monday in the quarter, etc). Sure you can > stuff it into a function, but it just isn't as maintainable as a table. So far I haven't been bothered with anything more complex than "clean" weeks, months, quarters, etc. I suppose the strongest argument for introducing date dimensions already now is that I probably will benefit from having conform and well-designed dimensions when I will be introducing more data marts. As for now I have only one fact table and some few dimensions in the system.
