org.apache.flink.table.planner.functions.aggfunctions

Class AvgAggFunction

java.lang.Object

org.apache.flink.table.functions.UserDefinedFunction

org.apache.flink.table.functions.DeclarativeAggregateFunction

org.apache.flink.table.planner.functions.aggfunctions.AvgAggFunction

All Implemented Interfaces:

Serializable, FunctionDefinition

Direct Known Subclasses:

AvgAggFunction.ByteAvgAggFunction, AvgAggFunction.DecimalAvgAggFunction, AvgAggFunction.DoubleAvgAggFunction, AvgAggFunction.FloatAvgAggFunction, AvgAggFunction.IntAvgAggFunction, AvgAggFunction.LongAvgAggFunction, AvgAggFunction.ShortAvgAggFunction

public abstract class AvgAggFunction
extends DeclarativeAggregateFunction

built-in avg aggregate function.

See Also:

Serialized Form

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	AvgAggFunction.ByteAvgAggFunction Built-in Byte Avg aggregate function.
static class	AvgAggFunction.DecimalAvgAggFunction Built-in Decimal Avg aggregate function.
static class	AvgAggFunction.DoubleAvgAggFunction Built-in Double Avg aggregate function.
static class	AvgAggFunction.FloatAvgAggFunction Built-in Float Avg aggregate function.
static class	AvgAggFunction.IntAvgAggFunction Built-in Integer Avg aggregate function.
static class	AvgAggFunction.LongAvgAggFunction Built-in Long Avg aggregate function.
static class	AvgAggFunction.ShortAvgAggFunction Built-in Short Avg aggregate function.

Constructor Summary

Constructors

Constructor and Description
AvgAggFunction()

Method Summary

Modifier and Type	Method and Description
Expression[]	accumulateExpressions() Expressions for accumulating the mutable aggregation buffer based on an input row.
protected UnresolvedCallExpression	adjustedMinus(UnresolvedReferenceExpression arg1, UnresolvedReferenceExpression arg2)
protected UnresolvedCallExpression	adjustedPlus(UnresolvedReferenceExpression arg1, UnresolvedReferenceExpression arg2)
UnresolvedReferenceExpression[]	aggBufferAttributes() All fields of the aggregate buffer.
DataType[]	getAggBufferTypes() All types of the aggregate buffer.
abstract DataType	getSumType()
Expression	getValueExpression() If all input are nulls, count will be 0 and we will get null after the division.
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.

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

getKind, getResultType, getTypeInference, 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, supportsConstantFolding

Constructor Detail

AvgAggFunction

public AvgAggFunction()

Method Detail

getSumType

public abstract DataType getSumType()

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

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()

If all input are nulls, count will be 0 and we will get null after the division.

Specified by:

getValueExpression in class DeclarativeAggregateFunction

adjustedPlus

protected UnresolvedCallExpression adjustedPlus(UnresolvedReferenceExpression arg1,
                                                UnresolvedReferenceExpression arg2)

adjustedMinus

protected UnresolvedCallExpression adjustedMinus(UnresolvedReferenceExpression arg1,
                                                 UnresolvedReferenceExpression arg2)