org.apache.hadoop.hive.ql.udf.generic
Class GenericUDAFEvaluator.AbstractAggregationBuffer

java.lang.Object
  org.apache.hadoop.hive.ql.udf.generic.GenericUDAFEvaluator.AbstractAggregationBuffer

All Implemented Interfaces:

GenericUDAFEvaluator.AggregationBuffer

Direct Known Subclasses:

GenericUDAFComputeStats.GenericUDAFBinaryStatsEvaluator.BinaryStatsAgg, GenericUDAFComputeStats.GenericUDAFBooleanStatsEvaluator.BooleanStatsAgg, GenericUDAFComputeStats.GenericUDAFDecimalStatsEvaluator.DecimalStatsAgg, GenericUDAFComputeStats.GenericUDAFDoubleStatsEvaluator.DoubleStatsAgg, GenericUDAFComputeStats.GenericUDAFLongStatsEvaluator.LongStatsAgg, GenericUDAFComputeStats.GenericUDAFStringStatsEvaluator.StringStatsAgg

Enclosing class:

GenericUDAFEvaluator

public abstract static class GenericUDAFEvaluator.AbstractAggregationBuffer
extends Object
implements GenericUDAFEvaluator.AggregationBuffer

Constructor Summary

GenericUDAFEvaluator.AbstractAggregationBuffer()

Method Summary

int	estimate() Estimate the size of memory which is occupied by aggregation buffer.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

GenericUDAFEvaluator.AbstractAggregationBuffer

public GenericUDAFEvaluator.AbstractAggregationBuffer()

Method Detail

estimate

public int estimate()

Estimate the size of memory which is occupied by aggregation buffer. Currently, hive assumes that primitives types occupies 16 byte and java object has 64 byte overhead for each. For map, each entry also has 64 byte overhead.