AggregatingAccumulator¶

AggregatingAccumulator is an AccumulatorV2 (Spark Core) for CollectMetricsExec physical operator.

AggregatingAccumulator accumulates InternalRows to produce an InternalRow.

AccumulatorV2[InternalRow, InternalRow]

Creating Instance¶

AggregatingAccumulator takes the following to be created:

• Buffer Schema (DataTypes)
• Initial Values Expressions
• Update Expressions
• Merge Expressions
• Result Expressions
• ImperativeAggregates
• TypedImperativeAggregates
• SQLConf

AggregatingAccumulator is created using apply and copyAndReset.

Creating AggregatingAccumulator¶

apply(
  functions: Seq[Expression],
  inputAttributes: Seq[Attribute]): AggregatingAccumulator

apply...FIXME

apply is used when:

• CollectMetricsExec physical operator is requested the accumulator

copyAndReset¶

copyAndReset(): AggregatingAccumulator

copyAndReset is part of the AccumulatorV2 (Spark Core) abstraction.

copyAndReset...FIXME