$extendedStats

$extendedStats returns $stats plus additional distribution metrics.

In addition to count, sum, min, max, and avg, this operator provides:

• sumOfSquares
• variance, variancePopulation, varianceSampling
• stdDeviation, stdDeviationPopulation, stdDeviationSampling
• stdDeviationBounds (upper, lower, plus sampling/population variants)

sigma controls the width of stdDeviationBounds.

Compatibility

Field Type	Supported
TEXT	No
U64/I64/F64	Yes
DATE	Yes
BOOL	No
KEYWORD	No
FACET	No

Field must be FAST.

Arguments

Argument	Type	Required	Description
field	string	Yes	Field to aggregate.
missing	number	No	Fallback value for missing fields.
sigma	number	No	Multiplier used for standard deviation bounds.

TypeScript

await index.aggregate({
  aggregations: {
    price_extended: {
      $extendedStats: { field: "price", sigma: 2, missing: 0 },
    },
  },
});

Python

index.aggregate(
    aggregations={
        "price_extended": {
            "$extendedStats": {"field": "price", "sigma": 2, "missing": 0}
        }
    }
)

Redis CLI

SEARCH.AGGREGATE products '{}' '{"price_extended": {"$extendedStats": {"field": "price", "sigma": 2, "missing": 0}}}'

Output

Returns a single object containing all basic and extended fields. Example shape:

{ "price_extended": {
    "count": 9, "min": 0, "max": 80, "avg": 40, "sum": 360,
    "sumOfSquares": 18000, "variance": 200, "stdDeviation": 14.14,
    "stdDeviationBounds": { "upper": 68.28, "lower": 11.72 }
  }
}