ClickHouse/docs/en/sql-reference/aggregate-functions/reference/maxintersectionsposition.md

64 lines
1.4 KiB
Markdown
Raw Normal View History

2023-01-12 00:10:51 +00:00
---
slug: /en/sql-reference/aggregate-functions/reference/maxintersectionsposition
2024-06-24 12:32:52 +00:00
sidebar_position: 164
2023-01-12 00:10:51 +00:00
title: maxIntersectionsPosition
---
# maxIntersectionsPosition
Aggregate function that calculates the positions of the occurrences of the [`maxIntersections` function](./maxintersections.md).
The syntax is:
```sql
maxIntersectionsPosition(start_column, end_column)
```
**Arguments**
- `start_column` the numeric column that represents the start of each interval. If `start_column` is `NULL` or 0 then the interval will be skipped.
- `end_column` - the numeric column that represents the end of each interval. If `end_column` is `NULL` or 0 then the interval will be skipped.
**Returned value**
Returns the start positions of the maximum number of intersected intervals.
**Example**
```sql
CREATE TABLE my_events (
start UInt32,
end UInt32
)
Engine = MergeTree
ORDER BY tuple();
INSERT INTO my_events VALUES
(1, 3),
(1, 6),
(2, 5),
(3, 7);
```
The intervals look like the following:
```response
1 - 3
1 - - - - 6
2 - - 5
3 - - - 7
```
Notice that three of these intervals have the value 4 in common, and that starts with the 2nd interval:
```sql
SELECT maxIntersectionsPosition(start, end) FROM my_events;
```
Response:
```response
2
```
In other words, the `(1,6)` row is the start of the 3 intervals that intersect, and 3 is the maximum number of intervals that intersect.