Table of Contents

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  1. Preface
  2. Transformations
  3. Source transformation
  4. Target transformation
  5. Aggregator transformation
  6. Cleanse transformation
  7. Data Masking transformation
  8. Deduplicate transformation
  9. Expression transformation
  10. Filter transformation
  11. Hierarchy Builder transformation
  12. Hierarchy Parser transformation
  13. Hierarchy Processor transformation
  14. Input transformation
  15. Java transformation
  16. Java transformation API reference
  17. Joiner transformation
  18. Labeler transformation
  19. Lookup transformation
  20. Mapplet transformation
  21. Normalizer transformation
  22. Output transformation
  23. Parse transformation
  24. Python transformation
  25. Rank transformation
  26. Router transformation
  27. Rule Specification transformation
  28. Sequence Generator transformation
  29. Sorter transformation
  30. SQL transformation
  31. Structure Parser transformation
  32. Transaction Control transformation
  33. Union transformation
  34. Velocity transformation
  35. Verifier transformation
  36. Web Services transformation

Transformations

Transformations

Partition and order keys

Partition and order keys

Configure partition and order keys to form groups of rows and define the order or sequence of rows within each partition.
Use the following keys to group and order the rows in a window:
Partition keys
Configure partition keys to define partition boundaries rather than performing the calculation across all rows.
If you do not specify partition keys, all the data is included in the same partition.
Order keys
Use order keys to determine how rows in a partition are ordered. Order keys define the position of a particular row in a partition.
You must also arrange the data in ascending or descending order. If you do not specify order keys, the rows in a partition are arranged randomly.
Consider the following rules and guidelines when you define window properties for partition and order keys:
  • You cannot use hierarchical fields as partition or order keys.
  • Define unique fields as partition and order keys.

Example

You are the owner of a coffee and tea shop. You want to calculate the best-selling and second best-selling coffee and tea products.
The following table lists the products, the corresponding product categories, and the revenue from each product:
Product
Category
Revenue
Espresso
Coffee
600
Black
Tea
550
Cappuccino
Coffee
500
Americano
Coffee
600
Oolong
Tea
250
Macchiato
Coffee
300
Green
Tea
450
White
Tea
650
You partition the data by category and order the data by descending revenue.
The following table shows the data grouped into two partitions according to category. Within each partition, the revenue is organized in descending order:
Product
Category
Revenue
Espresso
Coffee
600
Americano
Coffee
600
Cappuccino
Coffee
500
Macchiato
Coffee
300
White
Tea
650
Black
Tea
550
Green
Tea
450
Oolong
Tea
250
You can run the MAX function within each partition to determine that the two best-selling coffees are espresso and Americano, and the two best-selling teas are white and black.