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uniqTheta functions

uniqTheta functions work for two uniqThetaSketch objects to do set operation calculations such as ∪ / ∩ / × (union/intersect/not), it is to return a new uniqThetaSketch object contain the result.

A uniqThetaSketch object is to be constructed by aggregation function uniqTheta with -State.

UniqThetaSketch is a data structure storage of approximate values set. For more information on RoaringBitmap, see: Theta Sketch Framework.

uniqThetaUnion​

Two uniqThetaSketch objects to do union calculation(set operation ∪), the result is a new uniqThetaSketch.

uniqThetaUnion(uniqThetaSketch,uniqThetaSketch)

Arguments

  • uniqThetaSketch – uniqThetaSketch object.

Example

SELECT finalizeAggregation(uniqThetaUnion(a, b)) AS a_union_b, finalizeAggregation(a) AS a_cardinality, finalizeAggregation(b) AS b_cardinality
FROM
(SELECT arrayReduce('uniqThetaState',[1,2]) AS a, arrayReduce('uniqThetaState',[2,3,4]) AS b );

┌─a_union_b─┬─a_cardinality─┬─b_cardinality─┐
│         4 │             2 │             3 │
└───────────┴───────────────┴───────────────┘

uniqThetaIntersect​

Two uniqThetaSketch objects to do intersect calculation(set operation ∩), the result is a new uniqThetaSketch.

uniqThetaIntersect(uniqThetaSketch,uniqThetaSketch)

Arguments

  • uniqThetaSketch – uniqThetaSketch object.

Example

SELECT finalizeAggregation(uniqThetaIntersect(a, b)) AS a_intersect_b, finalizeAggregation(a) AS a_cardinality, finalizeAggregation(b) AS b_cardinality
FROM
(SELECT arrayReduce('uniqThetaState',[1,2]) AS a, arrayReduce('uniqThetaState',[2,3,4]) AS b );

┌─a_intersect_b─┬─a_cardinality─┬─b_cardinality─┐
│             1 │             2 │             3 │
└───────────────┴───────────────┴───────────────┘

uniqThetaNot​

Two uniqThetaSketch objects to do a_not_b calculation(set operation ×), the result is a new uniqThetaSketch.

uniqThetaNot(uniqThetaSketch,uniqThetaSketch)

Arguments

  • uniqThetaSketch – uniqThetaSketch object.

Example

SELECT finalizeAggregation(uniqThetaNot(a, b)) AS a_not_b, finalizeAggregation(a) AS a_cardinality, finalizeAggregation(b) AS b_cardinality
FROM
(SELECT arrayReduce('uniqThetaState',[2,3,4]) AS a, arrayReduce('uniqThetaState',[1,2]) AS b );

┌─a_not_b─┬─a_cardinality─┬─b_cardinality─┐
│       2 │             3 │             2 │
└─────────┴───────────────┴───────────────┘

See Also