Details
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New Feature
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Status: Closed
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Major
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Resolution: Fixed
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None
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Description
Projection Operator will allow apex users to project (select/drop) certain fields from the incoming tuples. This operation might be done unconditionally or based on certain condition.
Use case:
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Not all fields of tuples are of interest for the downstream operators. In such cases, one may want project selective fields to downstream. Also one may want to drop few fields, instead of selecting many.
In certain scenarios, one may want to project certain fields based on given condition or expression.
Functionality:
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1. Projection operator shall receive POJO as input tuple and emit 2 POJOs on separate output ports i.e. selected and dropped. Selected output port shall emit POJO with selected fields and dropped output shall emit POJO of dropped fields.
2. Operator needs select or drop fields as input params. This shall be specified using comma separated list of fields.
3. Operator shall emit POJO only on connected output ports. In another words, if dropped output port is not connected, it shall not even try to generate POJOs with dropped fields.