{
    "queryType": "topN",
    "dataSource": "wiki",
    "dimension": "regionIsoCode",
    "threshold": 5,
    "metric": "user_sketch",
    "aggregations": [
        {
            "type": "arrayOfDoublesSketch",
            "name": "user_sketch",
            "fieldName": "user",
            "metricColumns": ["sum_added", "sum_commentLength"],
            "numberOfValues": 2
        }
    ],
    "postAggregations": [
        {
            "type": "arrayOfDoublesSketchToMeans",
            "name": "means",
            "field": {
                "type": "fieldAccess",
                "name": "user_sketch",
                "fieldName": "user_sketch"
            }
        },
        {
            "type" : "quantilesDoublesSketchToHistogram",
            "name": "quantile",
            "field" : {
                "type": "arrayOfDoublesSketchToQuantilesSketch",
                "name": "quantiles_sketch",
                "column": 1,
                "k": 16384,
                "field": {
                    "type": "fieldAccess",
                    "name": "user_sketch",
                    "fieldName": "user_sketch"
                }
            }
        }
    ],
    "granularity": "all",
    "intervals": [
        "2016-01-01/P1Y"
    ]
}

{
    "error": "Unknown exception",
    "errorClass": "org.apache.datasketches.SketchesArgumentException",
    "errorMessage": "Values must be unique, monotonically increasing and not NaN.",
    "host": "172.19.0.5:8083"
}