private void registerTheta() {
    SketchDescriptor sd = new SketchDescriptor("theta");
    sd.register(DATA_TO_SKETCH, org.apache.datasketches.hive.theta.DataToSketchUDAF.class);
    // FIXME: missing?
    //registerUDF(org.apache.datasketches.hive.theta.SketchToStringUDF.class, p + SKETCH_TO_STRING);
    sd.register(UNION_SKETCH1, org.apache.datasketches.hive.theta.UnionSketchUDF.class);
    sd.register(UNION_SKETCH, org.apache.datasketches.hive.theta.UnionSketchUDAF.class);
    sd.register(INTERSECT_SKETCH1, org.apache.datasketches.hive.theta.IntersectSketchUDF.class);
    sd.register(INTERSECT_SKETCH, org.apache.datasketches.hive.theta.IntersectSketchUDAF.class);
    sd.register(SKETCH_TO_ESTIMATE, org.apache.datasketches.hive.theta.EstimateSketchUDF.class);
    sd.register(EXCLUDE_SKETCH, org.apache.datasketches.hive.theta.ExcludeSketchUDF.class);
    sketchClasses.put("theta", sd);

  }
Registers functions from the DataSketches library as builtin functions.

In an effort to show a more consistent
ql/src/java/org/apache/hadoop/hive/ql/exec/DataSketchesFunctions.java