abstract classAggregationIterator extends Iterator[UnsafeRow] with internal.Logging
The base class of SortBasedAggregationIterator and TungstenAggregationIterator.
It mainly contains two parts:
1. It initializes aggregate functions.
2. It creates two functions, processRow and generateOutput based on AggregateMode of
its aggregate functions. processRow is the function to handle an input. generateOutput
is used to generate result.
The base class of SortBasedAggregationIterator and TungstenAggregationIterator. It mainly contains two parts: 1. It initializes aggregate functions. 2. It creates two functions,
processRow
andgenerateOutput
based on AggregateMode of its aggregate functions.processRow
is the function to handle an input.generateOutput
is used to generate result.