docs/en/sql-reference/functions/uniqtheta-functions.md
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, see: Theta Sketch Framework.
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 │
└───────────┴───────────────┴───────────────┘
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 │
└───────────────┴───────────────┴───────────────┘
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
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