ab initio Rollup component with examples and detail explanation
Purpose
Rollup evaluates a group of input records that have the same key, and then generates records that either summarize each group or select certain information from each group.
Location in the Component Organizer
Transform folder
Recommendations
For new development, use Rollup rather than AGGREGATE. Rollup provides more control over record selection, grouping, and aggregation.
The behavior of ROLLUP varies in the presence of dirty data (NULLs or invalid values), according to whether you use the aggregation functions for the rollup:
Without aggregation functions, you can use ROLLUP normally.
With aggregation functions, always clean and validate data before rolling it up. Because the aggregation functions use a multistage transform, ROLLUP follows computation rules that may cause unexpected or even incorrect results in the presence of dirty data (NULLs or invalid values). Furthermore, the results will be hard to trace, particularly if the reject-threshold parameter is set to Never abort. Several factors — including the data type, the DML expression used to perform the rollup, and the value of the sorted-input parameter — may affect where the problems occur. It is safest to clean and validate the data before using the aggregation functions in ROLLUP.
Component folding can enhance the performance of this component. If this feature is enabled, the Co>Operating System folds this component by default. See “Component folding” for more information.
Then ROLLUP executes the following steps for each group of records:
Temporary initialization.
Computation.
Finalization.
Output selection.
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Purpose
Rollup evaluates a group of input records that have the same key, and then generates records that either summarize each group or select certain information from each group.
Location in the Component Organizer
Transform folder
Recommendations
Then ROLLUP executes the following steps for each group of records:
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