public class DataSetFinalAggFunction extends RichGroupReduceFunction<Row,Row> implements Compiler<GeneratedAggregations>, Logging
RichGroupReduceFunction
to compute the final result of a pre-aggregated aggregation
for batch (DataSet) queries.
param: genAggregations Code-generated GeneratedAggregations
Constructor and Description |
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DataSetFinalAggFunction(GeneratedAggregationsFunction genAggregations) |
Modifier and Type | Method and Description |
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void |
open(Configuration config)
Initialization method for the function.
|
void |
reduce(Iterable<Row> records,
Collector<Row> out)
The reduce method.
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close, getIterationRuntimeContext, getRuntimeContext, setRuntimeContext
public DataSetFinalAggFunction(GeneratedAggregationsFunction genAggregations)
public void open(Configuration config)
RichFunction
The configuration object passed to the function can be used for configuration and initialization. The configuration contains all parameters that were configured on the function in the program composition.
public class MyMapper extends FilterFunction<String> {
private String searchString;
public void open(Configuration parameters) {
this.searchString = parameters.getString("foo");
}
public boolean filter(String value) {
return value.equals(searchString);
}
}
By default, this method does nothing.
open
in interface RichFunction
open
in class AbstractRichFunction
config
- The configuration containing the parameters attached to the contract.Configuration
public void reduce(Iterable<Row> records, Collector<Row> out)
GroupReduceFunction
reduce
in interface GroupReduceFunction<Row,Row>
reduce
in class RichGroupReduceFunction<Row,Row>
records
- All records that belong to the given input key.out
- The collector to hand results to.Copyright © 2014–2018 The Apache Software Foundation. All rights reserved.