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

Defining rank groups

Defining rank groups

You can configure the Rank transformation to define groups for ranked rows. For example, to select the 10 most expensive items by manufacturer, define a rank group for the manufacturer. Define rank groups on the
Group By
tab.
To define rank groups, select one or more incoming fields as
Group By Fields
. For each unique value in a rank group, the transformation creates a group of rows that fall within the rank definition (top or bottom, and number in each rank).
Define rank groups to improve performance in an
elastic mapping
that processes a large volume of data. When you define rank groups, processing is distributed across multiple worker nodes. If you do not define rank groups, the data is processed on one worker node. Depending on the volume of data, performance is impacted and the mapping might fail due to a lack of storage space on the EBS volume that is attached to the worker node.
For example, you create a Rank transformation that ranks the top five salespersons grouped by quarter. The rank index numbers the salespeople from 1 to 5 for each quarter as follows:
RANKINDEX
SALES_PERSON
SALES
QUARTER
1
Alexandra B.
10000
1
2
Boris M.
9000
1
3
Chanchal R.
8000
1
4
Dong T.
7000
1
5
Elias M.
6000
1
1
Elias M.
11000
2
2
Boris M.
10000
2
3
Alexandra B.
9050
2
4
Dong T.
7500
2
5
Frances Z.
6900
2
If you define multiple rank groups, the Rank transformation groups the ranked rows in the order in which the fields are selected in the
Group By Fields
list.