org.apache.flink.table.functions

类 ImperativeAggregateFunction<T,ACC>

java.lang.Object

org.apache.flink.table.functions.UserDefinedFunction

org.apache.flink.table.functions.ImperativeAggregateFunction<T,ACC>

类型参数:

T - final result type of the aggregation

ACC - intermediate result type during the aggregation

所有已实现的接口:

Serializable, FunctionDefinition

直接已知子类:

AggregateFunction, TableAggregateFunction

@PublicEvolving
public abstract class ImperativeAggregateFunction<T,ACC>
extends UserDefinedFunction

Base class for user-defined AggregateFunction and TableAggregateFunction.

This class is used for unified handling of imperative aggregating functions. Concrete implementations should extend from AggregateFunction or TableAggregateFunction.

另请参阅:

序列化表格

构造器概要

构造器

构造器和说明
ImperativeAggregateFunction()

方法概要

限定符和类型	方法和说明
abstract ACC	createAccumulator() Creates and initializes the accumulator for this ImperativeAggregateFunction.
org.apache.flink.api.common.typeinfo.TypeInformation<ACC>	getAccumulatorType() 已过时。 This method uses the old type system and is based on the old reflective extraction logic. The method will be removed in future versions and is only called when using the deprecated TableEnvironment.registerFunction(...) method. The new reflective extraction logic (possibly enriched with DataTypeHint and FunctionHint) should be powerful enough to cover most use cases. For advanced users, it is possible to override UserDefinedFunction.getTypeInference(DataTypeFactory).
org.apache.flink.api.common.typeinfo.TypeInformation<T>	getResultType() 已过时。 This method uses the old type system and is based on the old reflective extraction logic. The method will be removed in future versions and is only called when using the deprecated TableEnvironment.registerFunction(...) method. The new reflective extraction logic (possibly enriched with DataTypeHint and FunctionHint) should be powerful enough to cover most use cases. For advanced users, it is possible to override UserDefinedFunction.getTypeInference(DataTypeFactory).

从类继承的方法 org.apache.flink.table.functions.UserDefinedFunction

close, functionIdentifier, getTypeInference, open, toString

从类继承的方法 java.lang.Object

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

从接口继承的方法 org.apache.flink.table.functions.FunctionDefinition

getKind, getRequirements, isDeterministic

构造器详细资料

ImperativeAggregateFunction

public ImperativeAggregateFunction()

方法详细资料

createAccumulator

public abstract ACC createAccumulator()

Creates and initializes the accumulator for this ImperativeAggregateFunction.

The accumulator is an intermediate data structure that stores the aggregated values until a final aggregation result is computed.

返回:

the accumulator with the initial value

getResultType

@Deprecated
public org.apache.flink.api.common.typeinfo.TypeInformation<T> getResultType()

已过时。 This method uses the old type system and is based on the old reflective extraction logic. The method will be removed in future versions and is only called when using the deprecated TableEnvironment.registerFunction(...) method. The new reflective extraction logic (possibly enriched with DataTypeHint and FunctionHint) should be powerful enough to cover most use cases. For advanced users, it is possible to override UserDefinedFunction.getTypeInference(DataTypeFactory).

Returns the TypeInformation of the ImperativeAggregateFunction's result.

返回:

The TypeInformation of the ImperativeAggregateFunction's result or null if the result type should be automatically inferred.

getAccumulatorType

@Deprecated
public org.apache.flink.api.common.typeinfo.TypeInformation<ACC> getAccumulatorType()

已过时。 This method uses the old type system and is based on the old reflective extraction logic. The method will be removed in future versions and is only called when using the deprecated TableEnvironment.registerFunction(...) method. The new reflective extraction logic (possibly enriched with DataTypeHint and FunctionHint) should be powerful enough to cover most use cases. For advanced users, it is possible to override UserDefinedFunction.getTypeInference(DataTypeFactory).

Returns the TypeInformation of the ImperativeAggregateFunction's accumulator.

返回:

The TypeInformation of the ImperativeAggregateFunction's accumulator or null if the accumulator type should be automatically inferred.