![]() ![]() See Window function categories for more detailed groupings of window functions. To ensure a unique sort order without duplicate values, use multi-column sorting criteria to clearly define how to handle duplicate values. Many window functions only work if the table is uniquely sorted by a column in the same “window” as the function. Without the grouping, the “window” is the entire table.įor most window functions, the results depend on the sort order of rows within the window. ![]() ![]() For example, if you group a table of city populations by State and then Rank it by city size of population, you get an independent ranking for each State. Sigma defines the “window” by the grouping level, and calculates results only from the rows within the window. You must therefore apply sort to every grouping level at or above the level where the function executes, to achieve correct results. Window functions results dependent on the order and grouping of rows. ![]()
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