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Dear Lenz: I posted this comment (or tried to) for the article written a couple of years ago regarding Rolling Sums. Since the article is old, I thought I would contact you directly. Basically, I have run into an interesting complication regarding Rolling Sums and Averages. The approach suggested in the article by Jay Pipes works great, and I have used it successfully with php code and graphical output as well. Now, here is the complication that I have been wrestling with for some time, and I really could use a "point" in the right direction. What would have happenned if the original scenario had included "feeds" of different types such as "questions," "answers," "complaints," "comments," etc. with the type being identified in a "type" column. I believe the approach presented would still lump all the different kinds into the same sum, even if we GROUP BY the type column. At least that is the problem I am having. I have a database with many performance indicators, each of which is identified in an ID column, and each of which could have data for any or all days in a year. I am trying to produced a running sum (Year-to-date) output column, but I need to have each of the performance indicators "sum" independently, and I need to preserve the date association. In other words, I need an output that shows all dates of a given year and the YTD value at each date and for each performance indicator in the database. To the best of my knowledge, the approach shown in Jay's article will not produce the desired results. Have you wrestled with the same complication? Could you offer some help in this regard? Thanks in advance, Charles Standard