Moment Sketches for Approximate Quantiles module

    To use this Apache Druid extension, make sure you include the extension in your config file:

    The aggregator operates over raw data while the momentSketchMerge aggregator should be used when aggregating precomputed sketches.

    1. {
    2.   "type" : <aggregator_type>,
    3.   "name" : <output_name>,
    4.   "fieldName" : <input_name>,
    5.   "k" : <int>,
    6.   "compress" : <boolean>
    7.  }

    Users can also query for the min/max of a distribution:

    1. {
    2.   "type" : "momentSketchMin" | "momentSketchMax",
    4. }

    and make queries using the following aggregator + post-aggregator:

    1. {
    2.   "aggregations": [{
    3.     "type": "momentSketchMerge",
    4.     "name": "sketch",
    5.     "fieldName": "sketch",
    6.     "k": 10,
    7.     "compress": true
    8.   }],
    9.   "postAggregations": [
    10.   {
    11.     "type": "momentSketchSolveQuantiles",
    13.     "field": {
    14.       "type": "fieldAccess",
    15.       "fieldName": "sketch"
    16.     }
    17.   },
    18.   {
    19.     "type": "momentSketchMin",
    20.     "name": "min",
    21.     "field": {
    22.       "type": "fieldAccess",
    23.       "fieldName": "sketch"
    24.     }