Compound/Multi-metric Grouping Results

Multi-metric aggregate queries can also use compound grouping. That is, a single aggregate query can specify multiple metric functions in the &m parameter and multiple GROUP functions in the &f or &cf parameter. Such queries compute multiple metric functions, like a multi-metric query, and provide multiple grouping operations for each metric, all in a single query.

The results of compound/multi-metric queries are returned using groupset elements for each combination of metric function and GROUP function. If there are m metric functions and n GROUP functions, the result will contain m x n groupset elements. Each groupset identifies the metric and grouping parameter for which it provides results.

As an example, the following compound/multi-metric aggregate query has 3 metric functions and 2 GROUP functions:

GET /Msgs/Message/_aggregate?m=COUNT(*),MAX(Size),AVERAGE(Size)
&cf=GROUP(TOP(2,Tags),Subject),GROUP(TRUNCATE(SendDate,DAY))

This means the result will contain 6 groupset elements, as shown in the following XML outline:

<results>

<aggregate metric="COUNT(*),MAX(Size),AVERAGE(Size)" group="GROUP(TOP(2,Tags),Subject),GROUP(TRUNCATE(SendDate,DAY))"/>

<groupsets>

<groupset group="TOP(2,Tags),Subject" metric="COUNT(*)">...</groupset>

<groupset group="TRUNCATE(SendDate,DAY)" metric="COUNT(*)">...</groupset>

<groupset group="TOP(2,Tags),Subject" metric="MAX(Size)">...</groupset>

<groupset group="TRUNCATE(SendDate,DAY)" metric="MAX(Size)">...</groupset>

<groupset group="TOP(2,Tags),Subject" metric="AVERAGE(Size)">...</groupset>

<groupset group="TRUNCATE(SendDate,DAY)" metric="AVERAGE(Size)">...</groupset>

</groupsets>

</results>

In JSON:

{"results": {

"aggregate": {

"group": "GROUP(TOP(2,Tags),Origin),GROUP(TRUNCATE(SendDate,DAY))",

"metric": "COUNT(*),MAX(Size),AVERAGE(Size)"

},

"groupsets": [

{"groupset": {"group": "TOP(2,Subject),Origin", "metric": "COUNT(*)", ...}},

{"groupset": {"group": "TRUNCATE(SendDate,DAY)", "metric": "COUNT(*)", ...}},

{"groupset": {"group": "TOP(2,Subject),Origin", "metric": "MAX(Size)", ...}},

{"groupset": {"group": "TRUNCATE(SendDate,DAY)", "metric": "MAX(Size)", ...},

{"groupset": {"group": "TOP(2,Subject),Origin", "metric": "AVERAGE(Size)", ...}},

{"groupset": {"group": "TRUNCATE(SendDate,DAY)", "metric": "AVERAGE(Size)", ...}}

]

}}

Though not shown here, each groupset will contain groups, summary, and totalgroups elements as required by each GROUP function. If the query requests composite grouping (&cf), a groupset with multi-level grouping will contain a composite group for non-leaf groups.