Sorts a set and returns a subset from its higher-valued end, given a cutoff value that is applied to a total across elements.
Syntax and Details
TOPSUM(set_expression, cutoff_value, ordering_expression)
cutoff_value is a numeric literal.The function uses this argument to determine the cutoff value for elements to return in the subset.For all elements in the returned subset, the sum of the values of ordering_expression will be less than or equal to cutoff_value.
ordering_expression is a numeric-valued expression that determines the order of the set members.The function evaluates this expression for each element of the set and sorts the elements of the set in descending order according to this value. Any hierarchies are ignored.
First consider an example in which the cutoff value is high enough to include all members:
SELECT MEASURES.[%COUNT] ON 0, TOPSUM(birthd.decade.MEMBERS, 10000, MEASURES.[%COUNT]) ON 1 FROM patients Patient Count 1 1970s 1,520 2 1960s 1,500 3 2000s 1,433 4 1990s 1,413 5 1980s 1,400 6 1950s 1,030 7 1940s 683 8 1930s 572 9 1920s 223 10 2010s 155 11 1910s 71
Now consider a variation in which the cutoff value is set to 2500:
SELECT MEASURES.[%COUNT] ON 0, TOPSUM(birthd.decade.MEMBERS, 2500, MEASURES.[%COUNT]) ON 1 FROM patients Patient Count 1970s 1,520