WHERE TOP or BOTTOM(n) IN
WHERE TOP|BOTTOM IN is a ranking filter. It limits the inputs into a metric’s computations to those values that are the top or bottom n rankings according to the ranking criteria that you specify. This filter supports percent parameters: n%.
When you are using filters with a percentage (such as TOP(20%)), the number of the selected items is always rounded up.
For example, you want to select 20% of 21 items, and each item has a distinct value of the metric that it is ranked by. The result is going to be 5, because 20% of 21 is 4.2, and it gets rounded up to 5.
Syntax
SELECT … WHERE TOP(…) IN … WITHIN …
SELECT metric1 WHERE TOP(n) IN (SELECT metric2 BY attribute1, attribute2...) WITHIN (...)
Here, metric1 represents the metric whose value is actually returned. The value returned depends on which values are included in its computations. These inputs are determined by the filtering criteria statement that follows the IN keyword in parentheses.
The attributes following BY are those that will be ranked according to their metric2 values. Whichever attribute values are associated with metric2 values that fall in the TOP(n) or BOTTOM(n) are then included in metric1 computations – determining the final output.
The syntax for this type of rank filtering requires the SELECT keyword before the metric following the IN keyword.
Examples
SELECT #tickets WHERE TOP(5) IN (SELECT #tickets 2 BY assignee) WITHIN (ticket group, all other)
This example returns TOP(#) assignees by EACH group.
SELECT Amount WHERE TOP(5) IN (SELECT Avg. Won BY Product)
MAQL also supports using an OF keyword following the TOP|BOTTOM ranking filter. This changes the way the metric is interpreted by the query engine. With OF you can carry out rankings by more than one metric. Likewise, the ranking metric is interpreted as a submetric, rather than a subreport (as is the case for TOP|BOTTOM in conjunction with the IN keyword).
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