mirror of
https://github.com/ClickHouse/ClickHouse.git
synced 2024-11-15 12:14:18 +00:00
95 lines
3.1 KiB
Markdown
95 lines
3.1 KiB
Markdown
---
|
||
slug: /en/sql-reference/functions/uniqtheta-functions
|
||
---
|
||
|
||
# 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](https://datasketches.apache.org/docs/Theta/ThetaSketchFramework.html).
|
||
|
||
## uniqThetaUnion
|
||
|
||
Two uniqThetaSketch objects to do union calculation(set operation ∪), the result is a new uniqThetaSketch.
|
||
|
||
``` sql
|
||
uniqThetaUnion(uniqThetaSketch,uniqThetaSketch)
|
||
```
|
||
|
||
**Arguments**
|
||
|
||
- `uniqThetaSketch` – uniqThetaSketch object.
|
||
|
||
**Example**
|
||
|
||
``` sql
|
||
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 );
|
||
```
|
||
|
||
``` text
|
||
┌─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.
|
||
|
||
``` sql
|
||
uniqThetaIntersect(uniqThetaSketch,uniqThetaSketch)
|
||
```
|
||
|
||
**Arguments**
|
||
|
||
- `uniqThetaSketch` – uniqThetaSketch object.
|
||
|
||
**Example**
|
||
|
||
``` sql
|
||
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 );
|
||
```
|
||
|
||
``` text
|
||
┌─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.
|
||
|
||
``` sql
|
||
uniqThetaNot(uniqThetaSketch,uniqThetaSketch)
|
||
```
|
||
|
||
**Arguments**
|
||
|
||
- `uniqThetaSketch` – uniqThetaSketch object.
|
||
|
||
**Example**
|
||
|
||
``` sql
|
||
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 );
|
||
```
|
||
|
||
``` text
|
||
┌─a_not_b─┬─a_cardinality─┬─b_cardinality─┐
|
||
│ 2 │ 3 │ 2 │
|
||
└─────────┴───────────────┴───────────────┘
|
||
```
|
||
|
||
**See Also**
|
||
|
||
- [uniqThetaSketch](../../sql-reference/aggregate-functions/reference/uniqthetasketch.md#agg_function-uniqthetasketch)
|