Produces output similar to using SELECT ... GROUP BY ... SQL statements. Each grouping is defined in the aggregationSets element which defines grouping key components and a set of aggregating expressions. Component values and aggregated results are collected into new output records which are sent to the out_results endpoint.

<step id='groupAggregator' className='cz.adastra.cif.tasks.analysis.aggregator.GroupAggregator'>
        <properties>
                <aggregationSets>
                        <aggregationSet when="client_type=='F'">
                                <aggregations>
                                        <aggregation name="count" expression="count()"/>
                                        <aggregation name="max_score" expression="maximum(score)"/>
                                </aggregations>
                                <groupBy>
                                        <component name="nationality" expression="src_nationality"/>
                                </groupBy>
                        </aggregationSet>
                        <aggregationSet when="score > 0">
                                <aggregations>
                                        <aggregation name="count" expression="count()"/>
                                </aggregations>
                                <groupBy>
                                        <component name="score_range"
                                                expression="case(score < 100, 100, score < 500, 500, 1000)"/>
                                </groupBy>
                        </aggregationSet>
                </aggregationSets>
        </properties>
</step>