/** * Evaluate Druid query for expensive aggregation that could bring down Druid. * * @param query Druid Query * * @return query or null if not required */ public static WeightEvaluationQuery makeWeightEvaluationQuery(DruidAggregationQuery<?> query) { // get inner-most query for evaluation DruidAggregationQuery<?> innerQuery = query.getInnermostQuery(); int weight = Utils.getSubsetByType(innerQuery.getAggregations(), SketchAggregation.class).size(); return new WeightEvaluationQuery(innerQuery, weight); }