org.apache.flink.table.functions.hive

Class HiveAverageAggFunction

java.lang.Object

org.apache.flink.table.functions.UserDefinedFunction

org.apache.flink.table.functions.DeclarativeAggregateFunction

org.apache.flink.table.functions.hive.HiveDeclarativeAggregateFunction

org.apache.flink.table.functions.hive.HiveAverageAggFunction

All Implemented Interfaces:

Serializable, FunctionDefinition

public class HiveAverageAggFunction
extends HiveDeclarativeAggregateFunction

built-in hive average aggregate function.

See Also:

Serialized Form

Field Summary

Fields inherited from class org.apache.flink.table.functions.hive.HiveDeclarativeAggregateFunction

MAX_SCALE

Constructor Summary

Constructors

Constructor and Description
HiveAverageAggFunction()

Method Summary

Modifier and Type	Method and Description
Expression[]	accumulateExpressions() Expressions for accumulating the mutable aggregation buffer based on an input row.
UnresolvedReferenceExpression[]	aggBufferAttributes() All fields of the aggregate buffer.
DataType[]	getAggBufferTypes() All types of the aggregate buffer.
DataType	getResultType() The result type of the function.
Expression	getValueExpression() An expression which returns the final value for this aggregate function.
Expression[]	initialValuesExpressions() Expressions for initializing empty aggregation buffers.
Expression[]	mergeExpressions() A sequence of expressions for merging two aggregation buffers together.
int	operandCount() How many operands your function will deal with.
Expression[]	retractExpressions() Expressions for retracting the mutable aggregation buffer based on an input row.
void	setArguments(CallContext callContext) Set input arguments for the function if need some inputs to infer the aggBuffer type and result type.

Methods inherited from class org.apache.flink.table.functions.hive.HiveDeclarativeAggregateFunction

adjustedPlus, checkArgumentNum, checkMinMaxArgumentType, getKind, getTypeInference

Methods inherited from class org.apache.flink.table.functions.DeclarativeAggregateFunction

mergeOperand, mergeOperands, operand, operands

Methods inherited from class org.apache.flink.table.functions.UserDefinedFunction

close, functionIdentifier, open, toString

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.flink.table.functions.FunctionDefinition

getRequirements, isDeterministic

Constructor Detail

HiveAverageAggFunction

public HiveAverageAggFunction()

Method Detail

operandCount

public int operandCount()

Description copied from class: DeclarativeAggregateFunction

How many operands your function will deal with.

Specified by:

operandCount in class DeclarativeAggregateFunction

aggBufferAttributes

public UnresolvedReferenceExpression[] aggBufferAttributes()

Description copied from class: DeclarativeAggregateFunction

All fields of the aggregate buffer.

Specified by:

aggBufferAttributes in class DeclarativeAggregateFunction

getAggBufferTypes

public DataType[] getAggBufferTypes()

Description copied from class: DeclarativeAggregateFunction

All types of the aggregate buffer.

Specified by:

getAggBufferTypes in class DeclarativeAggregateFunction

getResultType

public DataType getResultType()

Description copied from class: DeclarativeAggregateFunction

The result type of the function.

Specified by:

getResultType in class DeclarativeAggregateFunction

initialValuesExpressions

public Expression[] initialValuesExpressions()

Description copied from class: DeclarativeAggregateFunction

Expressions for initializing empty aggregation buffers.

Specified by:

initialValuesExpressions in class DeclarativeAggregateFunction

accumulateExpressions

public Expression[] accumulateExpressions()

Description copied from class: DeclarativeAggregateFunction

Expressions for accumulating the mutable aggregation buffer based on an input row.

Specified by:

accumulateExpressions in class DeclarativeAggregateFunction

retractExpressions

public Expression[] retractExpressions()

Description copied from class: DeclarativeAggregateFunction

Expressions for retracting the mutable aggregation buffer based on an input row.

Specified by:

retractExpressions in class DeclarativeAggregateFunction

mergeExpressions

public Expression[] mergeExpressions()

Description copied from class: DeclarativeAggregateFunction

A sequence of expressions for merging two aggregation buffers together. When defining these expressions, you can use the syntax attributeName and mergeOperand(attributeName) to refer to the attributes corresponding to each of the buffers being merged.

Specified by:

mergeExpressions in class DeclarativeAggregateFunction

getValueExpression

public Expression getValueExpression()

Description copied from class: DeclarativeAggregateFunction

An expression which returns the final value for this aggregate function.

Specified by:

getValueExpression in class DeclarativeAggregateFunction

setArguments

public void setArguments(CallContext callContext)

Description copied from class: HiveDeclarativeAggregateFunction

Set input arguments for the function if need some inputs to infer the aggBuffer type and result type. Otherwise, just implements it do nothing.

Specified by:

setArguments in class HiveDeclarativeAggregateFunction