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

Class RankLikeAggFunctionBase

java.lang.Object

org.apache.flink.table.functions.UserDefinedFunction

org.apache.flink.table.functions.DeclarativeAggregateFunction

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

All Implemented Interfaces:

Serializable, FunctionDefinition

Direct Known Subclasses:

DenseRankAggFunction, RankAggFunction

public abstract class RankLikeAggFunctionBase
extends DeclarativeAggregateFunction

built-in rank like aggregate function, e.g. rank, dense_rank

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
protected UnresolvedReferenceExpression[]	lastValues
protected LogicalType[]	orderKeyTypes
protected UnresolvedReferenceExpression	sequence

Constructor Summary

Constructors

Constructor and Description
RankLikeAggFunctionBase(LogicalType[] orderKeyTypes)

Method Summary

Modifier and Type	Method and Description
protected Expression	generateInitLiteral(LogicalType orderType)
DataType	getResultType() The result type of the function.
Expression	getValueExpression() An expression which returns the final value for this aggregate function.
Expression[]	mergeExpressions() A sequence of expressions for merging two aggregation buffers together.
int	operandCount() How many operands your function will deal with.
protected Expression	orderKeyEqualsExpression()
Expression[]	retractExpressions() Expressions for retracting the mutable aggregation buffer based on an input row.

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

accumulateExpressions, aggBufferAttributes, getAggBufferTypes, getKind, getTypeInference, initialValuesExpressions, 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

Field Detail

sequence

protected UnresolvedReferenceExpression sequence

lastValues

protected UnresolvedReferenceExpression[] lastValues

orderKeyTypes

protected LogicalType[] orderKeyTypes

Constructor Detail

RankLikeAggFunctionBase

public RankLikeAggFunctionBase(LogicalType[] orderKeyTypes)

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

getResultType

public DataType getResultType()

Description copied from class: DeclarativeAggregateFunction

The result type of the function.

Specified by:

getResultType 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

orderKeyEqualsExpression

protected Expression orderKeyEqualsExpression()

generateInitLiteral

protected Expression generateInitLiteral(LogicalType orderType)