Top rows（顶行选取（Top rows））¶
Supported in: Batch, Faster
Picks the top rows in each sorted partition.
Transform categories: Aggregate
Declared arguments¶
- Dataset: Input dataset.
Table - Partition by columns: Set of columns to determine each partition from.
Set\ - Sort specification: Specification for how to sort each partition. At least one specification is required.
List\ - optional Number of rows: Number of rows to select, defaults to 1.
Literal\
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 |
中文翻译¶
顶行选取（Top rows）¶
支持：批处理模式（Batch）、快速模式（Faster）
在每个已排序分区中选取顶行数据。
转换类别：聚合（Aggregate）
声明参数¶
- 数据集（Dataset）： 输入数据集。
表（Table） - 分区列（Partition by columns）： 用于确定每个分区的列集合。
Set\ - 排序规范（Sort specification）： 定义每个分区排序方式的规范。至少需要指定一个规范。
List\ - 可选 行数（Number of rows）： 要选取的行数，默认为1。
Literal\
示例¶
示例1：基础情况¶
参数值：
- 数据集： ri.foundry.main.dataset.a
- 分区列： {
airline} - 排序规范： [(
airport,DESCENDING), (miles,ASCENDING)] - 行数： null
输入：
| 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 |
输出：
| airline | airport | miles |
|---|---|---|
| foundry airways | LHR | 2221324 |
| new air | SFO | 21356673 |
示例2：基础情况¶
参数值：
- 数据集： ri.foundry.main.dataset.a
- 分区列： {}
- 排序规范： [(
airline,DESCENDING), (airport,DESCENDING), (miles,ASCENDING)] - 行数： 2
输入：
| 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 |
输出：
| airline | airport | miles |
|---|---|---|
| new air | SFO | 21356673 |
| new air | JFK | 12232355 |
示例3：基础情况¶
参数值：
- 数据集： ri.foundry.main.dataset.a
- 分区列： {}
- 排序规范： []
- 行数： 1
输入：
| 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 |
输出：
| airline | airport | miles |
|---|---|---|
| foundry airways | JFK | 1002345 |