# Top rows

> Supported in: Batch, Faster

Picks the top rows in each sorted partition.

**Transform categories**: Aggregate

## Declared arguments

* **Dataset:** Input dataset.<br>*Table*
* **Partition by columns:** Set of columns to determine each partition from.<br>*Set\<Column\<AnyType>>*
* **Sort specification:** Specification for how to sort each partition. At least one specification is required.<br>*List\<Tuple\<Column\<AnyType>, Enum\<Ascending, Descending>>>*
* *optional* **Number of rows:** Number of rows to select, defaults to 1.<br>*Literal\<Integer>*

## Examples

### Example 1: Base case

**Argument values:**

* **Dataset:** ri.foundry.main.dataset.a
* **Partition by columns:** {`airline`}
* **Sort specification:** \[(`airport`, `DESCENDING`), (`miles`, `ASCENDING`)]
* **Number of rows:** *null*

**Input:**

| airline | airport | miles |
| ----- | ----- | ----- |
| foundry airways | JFK | 1002345 |
| foundry airways | LHR | 2221324 |
| new air | SFO | 21356673 |
| new air | JFK | 12323456 |
| foundry airways | LHR | 12542352 |
| new air | JFK | 12232355 |

**Output:**

| airline | airport | miles |
| ----- | ----- | ----- |
| foundry airways | LHR | 2221324 |
| new air | SFO | 21356673 |

***

### Example 2: Base case

**Argument values:**

* **Dataset:** ri.foundry.main.dataset.a
* **Partition by columns:** {}
* **Sort specification:** \[(`airline`, `DESCENDING`), (`airport`, `DESCENDING`), (`miles`, `ASCENDING`)]
* **Number of rows:** 2

**Input:**

| airline | airport | miles |
| ----- | ----- | ----- |
| foundry airways | JFK | 1002345 |
| foundry airways | LHR | 2221324 |
| new air | SFO | 21356673 |
| new air | JFK | 12323456 |
| foundry airways | LHR | 12542352 |
| new air | JFK | 12232355 |

**Output:**

| airline | airport | miles |
| ----- | ----- | ----- |
| new air | SFO | 21356673 |
| new air | JFK | 12232355 |

***

### Example 3: Base case

**Argument values:**

* **Dataset:** ri.foundry.main.dataset.a
* **Partition by columns:** {}
* **Sort specification:** \[]
* **Number of rows:** 1

**Input:**

| airline | airport | miles |
| ----- | ----- | ----- |
| foundry airways | JFK | 1002345 |
| foundry airways | LHR | 2221324 |
| new air | SFO | 21356673 |
| new air | JFK | 12323456 |
| foundry airways | LHR | 12542352 |
| new air | JFK | 12232355 |

**Output:**

| airline | airport | miles |
| ----- | ----- | ----- |
| foundry airways | JFK | 1002345 |

***

### Example 4: Base case

**Argument values:**

* **Dataset:** ri.foundry.main.dataset.a
* **Partition by columns:** {}
* **Sort specification:** \[(`value`, `ASCENDING`)]
* **Number of rows:** 0

**Input:**

| value |
| ----- |
| 1 |
| 2 |

**Output:**

| value |
| ----- |

***