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Static Drift Operator

Given dimension and population metrics, compute a timeseries of drift metrics that measures the dimensional drift of the current data compared to a static baseline.

This operator requires two inputs: a timeseries dataset of new data and baseline dataset without a time component.

The dimension values can be encoded in two ways: enumeration or linear buckets.

  • The enumeration encoder should be used for string values or low-cardinality numeric values. New values encountered in the current data are always mapped the same integer, which corresponds to the other category.

  • The linear buckets encoder should be used for numerical values that have high cardinality. The linear buckets encoder maps each dimension value to a bucket index. All values less than the smallest bucket are mapped to the smallest bucket. All values larger than the largest bucket are mapped to the largest bucket.

At each timestamp, the operator computes a normalized EMD of the distribution of dimension values of the current data compared to the baseline data.

The EMD distance function depends on the encoding:

  • For enumeration, the distance used is always 1 / number of unique values.

  • For bucketing, the distance used is the normalized distance between the buckets.


currentDataA data frame with columns ts, dim, and met. Missing data is ok, and the time index filler is not recommended. Column ts is the timestamp. Column dim is the dimension to used to measure drift. Column met is the metric or population of the dimension value at the timestamp.
baselineDataA data frame with columns dim and met. The baseline data should not have a time component.


driftScoreDataThe resulting data frame of drift metrics. The data frame has columns ts and met. Column ts is the timestamp. Column met is the drift score computed at the timestamp.


Operator parameters

monitoringGranularityThe time granularity of the output timeseries.
encoderThe encoder parameters json object.

Encoder parameters

typeThe type of encoder. One of ENUMERATION or LINEAR_BUCKETS.
linearBucketThe linear bucket parameters json object.

Linear bucket parameters

bucketStartThe value corresponding to the first bucket.
bucketSizeThe size of each bucket.
bucketCountThe number of buckets to use.


  "name": "driftScore",
  "type": "StaticBaselineDrift",
  "params": {
    "encoder": {
      "type": "LINEAR_BUCKETS",
      "linearBucket": {
        "bucketStart": "0",
        "bucketSize": "1",
        "bucketCount": "100"
    "monitoringGranularity": "P1D"
  "inputs": [
      "targetProperty": "currentData",
      "sourcePlanNode": "currentDataFetcher",
      "sourceProperty": "currentData"
      "targetProperty": "baselineData",
      "sourcePlanNode": "baselineDataFetcher",
      "sourceProperty": "baselineData"
  "outputs": [
      "outputName": "driftScoreData"