transformations:aggregate
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transformations:aggregate [2014/10/25 18:34] – created dmitry | transformations:aggregate [2015/05/01 08:48] – dmitry | ||
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===== Aggregate ===== | ===== Aggregate ===== | ||
- | This transformation calculates aggregates for selected columns grouped by another set of columns. | + | This transformation calculates |
Available aggregations: | Available aggregations: | ||
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* Max | * Max | ||
+ | EXAMPLE | ||
+ | |||
+ | **Source table:** The longest rivers in the world | ||
+ | |||
+ | ^ River ^ Length(km) | ||
+ | | Nile | 6650 | Africa | ||
+ | | Amazon | ||
+ | | Yangtze | ||
+ | | Mississippi | ||
+ | | Yenisei | ||
+ | | Yellow River | 5464 | Asia | | ||
+ | | Ob | 5410 | Asia | | ||
+ | | Paraná | ||
+ | |||
+ | **Objective: | ||
+ | |||
+ | **Transformation parameters: | ||
+ | |||
+ | * Calculate: Length(km) | ||
+ | * Aggregation: | ||
+ | * Group by: Continent | ||
+ | |||
+ | **Output table:** | ||
+ | |||
+ | ^ River ^ Continent | ||
+ | | Nile | Africa | ||
+ | | Yangtze | ||
+ | | Mississippi | ||
+ | | Amazon | ||
transformations/aggregate.txt · Last modified: 2021/09/12 11:25 by craigt