mirror of
https://github.com/ClickHouse/ClickHouse.git
synced 2024-12-03 21:12:28 +00:00
40 lines
1.2 KiB
Markdown
40 lines
1.2 KiB
Markdown
---
|
|
toc_priority: 145
|
|
---
|
|
|
|
# sumKahan {#agg_function-sumKahan}
|
|
|
|
Calculates the sum of the numbers with [Kahan compensated summation algorithm](https://en.wikipedia.org/wiki/Kahan_summation_algorithm)
|
|
Slower than [sum](./sum.md) function.
|
|
The compensation works only for [Float](../../../sql-reference/data-types/float.md) types.
|
|
|
|
|
|
**Syntax**
|
|
|
|
``` sql
|
|
sumKahan(x)
|
|
```
|
|
|
|
**Arguments**
|
|
|
|
- `x` — Input value, must be [Integer](../../../sql-reference/data-types/int-uint.md), [Float](../../../sql-reference/data-types/float.md), or [Decimal](../../../sql-reference/data-types/decimal.md).
|
|
|
|
**Returned value**
|
|
|
|
- the sum of numbers, with type [Integer](../../../sql-reference/data-types/int-uint.md), [Float](../../../sql-reference/data-types/float.md), or [Decimal](../../../sql-reference/data-types/decimal.md) depends on type of input arguments
|
|
|
|
**Example**
|
|
|
|
Query:
|
|
|
|
``` sql
|
|
SELECT sum(0.1), sumKahan(0.1) FROM numbers(10);
|
|
```
|
|
|
|
Result:
|
|
|
|
``` text
|
|
┌───────────sum(0.1)─┬─sumKahan(0.1)─┐
|
|
│ 0.9999999999999999 │ 1 │
|
|
└────────────────────┴───────────────┘
|
|
``` |