What happens when you're reporting on a period greater than a year?

Won't both of the overlapping month's figures will be aggregated into a single month aggregate total?

magarity kerns (4/14/2010)

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rmd0 (4/14/2010)

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One issue I have with this solution is that MD5 *will* have collisions with moderately "wide" tables, especially when bit columns are involved. In fact, I would...