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>It seems in my experience with non-parallel that grouping does sort - >it has to sort things in order to get things in groups... My experience agrees with yours, grouping does result in a sorted list, but that's just a side effect of how they group. As for the "it HAS to sort" part, I can't speak for DB2/400, but you don't have to sort to group, just create enough buckets for your distinct values and drop the values into the buckets as you go. Think of "select state, count(*) from customer" you could sort on state and then count as you go, or you could create 50 buckets and simply pound the file in arrival order adding 1 to the approprite bucket for each row. Heck, with parallelism you could even have several threads pound the file (thread 1 from row 1 to 1M, thread 2 from row 1M+1 to 2M, thread 3...) and then add together the results at the end. -Walden ------------ Walden H Leverich III President & CEO Tech Software (516) 627-3800 x11 WaldenL@xxxxxxxxxxxxxxx http://www.TechSoftInc.com Quiquid latine dictum sit altum viditur. (Whatever is said in Latin seems profound.)
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