org.apache.flink.table.functions.python

类 PythonTableAggregateFunction

java.lang.Object

org.apache.flink.table.functions.UserDefinedFunction

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

org.apache.flink.table.functions.TableAggregateFunction

org.apache.flink.table.functions.python.PythonTableAggregateFunction

所有已实现的接口:

Serializable, FunctionDefinition, PythonFunction

@Internal
public class PythonTableAggregateFunction
extends TableAggregateFunction
implements PythonFunction

The wrapper of user defined python table aggregate function.

另请参阅:

序列化表格

嵌套类概要

从类继承的嵌套类/接口 org.apache.flink.table.functions.TableAggregateFunction

TableAggregateFunction.RetractableCollector<T>

构造器概要

构造器

构造器和说明
PythonTableAggregateFunction(String name, byte[] serializedTableAggregateFunction, DataType[] inputTypes, DataType resultType, DataType accumulatorType, PythonFunctionKind pythonFunctionKind, boolean deterministic, boolean takesRowAsInput, PythonEnv pythonEnv)

方法概要

限定符和类型	方法和说明
void	accumulate(Object accumulator, Object... args)
Object	createAccumulator() Creates and initializes the accumulator for this ImperativeAggregateFunction.
void	emitValue(Object accumulator, Object out)
org.apache.flink.api.common.typeinfo.TypeInformation	getAccumulatorType() Returns the TypeInformation of the ImperativeAggregateFunction's accumulator.
PythonEnv	getPythonEnv() Returns the Python execution environment.
PythonFunctionKind	getPythonFunctionKind() Returns the kind of the user-defined python function.
org.apache.flink.api.common.typeinfo.TypeInformation	getResultType() Returns the TypeInformation of the ImperativeAggregateFunction's result.
byte[]	getSerializedPythonFunction() Returns the serialized representation of the user-defined python function.
TypeInference	getTypeInference(DataTypeFactory typeFactory) Returns the logic for performing type inference of a call to this function definition.
boolean	isDeterministic() Returns information about the determinism of the function's results.
boolean	takesRowAsInput() Returns Whether the Python function takes row as input instead of each columns of a row.
String	toString() Returns the name of the UDF that is used for plan explanation and logging.

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

getKind

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

close, functionIdentifier, open

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

getRequirements

构造器详细资料

PythonTableAggregateFunction

public PythonTableAggregateFunction(String name,
                                    byte[] serializedTableAggregateFunction,
                                    DataType[] inputTypes,
                                    DataType resultType,
                                    DataType accumulatorType,
                                    PythonFunctionKind pythonFunctionKind,
                                    boolean deterministic,
                                    boolean takesRowAsInput,
                                    PythonEnv pythonEnv)

方法详细资料

accumulate

public void accumulate(Object accumulator,
                       Object... args)

emitValue

public void emitValue(Object accumulator,
                      Object out)

createAccumulator

public Object createAccumulator()

从类复制的说明: ImperativeAggregateFunction

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.

指定者:

createAccumulator 在类中 ImperativeAggregateFunction

返回:

the accumulator with the initial value

getSerializedPythonFunction

public byte[] getSerializedPythonFunction()

从接口复制的说明: PythonFunction

Returns the serialized representation of the user-defined python function.

指定者:

getSerializedPythonFunction 在接口中 PythonFunction

getPythonEnv

public PythonEnv getPythonEnv()

从接口复制的说明: PythonFunction

Returns the Python execution environment.

指定者:

getPythonEnv 在接口中 PythonFunction

getPythonFunctionKind

public PythonFunctionKind getPythonFunctionKind()

从接口复制的说明: PythonFunction

Returns the kind of the user-defined python function.

指定者:

getPythonFunctionKind 在接口中 PythonFunction

takesRowAsInput

public boolean takesRowAsInput()

从接口复制的说明: PythonFunction

Returns Whether the Python function takes row as input instead of each columns of a row.

指定者:

takesRowAsInput 在接口中 PythonFunction

isDeterministic

public boolean isDeterministic()

从接口复制的说明: FunctionDefinition

Returns information about the determinism of the function's results.

It returns true if and only if a call to this function is guaranteed to always return the same result given the same parameters. true is assumed by default. If the function is not purely functional like random(), date(), now(), ... this method must return false.

Furthermore, return false if the planner should always execute this function on the cluster side. In other words: the planner should not perform constant expression reduction during planning for constant calls to this function.

指定者:

isDeterministic 在接口中 FunctionDefinition

getResultType

public org.apache.flink.api.common.typeinfo.TypeInformation getResultType()

从类复制的说明: ImperativeAggregateFunction

Returns the TypeInformation of the ImperativeAggregateFunction's result.

覆盖:

getResultType 在类中 ImperativeAggregateFunction

返回:

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

getAccumulatorType

public org.apache.flink.api.common.typeinfo.TypeInformation getAccumulatorType()

从类复制的说明: ImperativeAggregateFunction

Returns the TypeInformation of the ImperativeAggregateFunction's accumulator.

覆盖:

getAccumulatorType 在类中 ImperativeAggregateFunction

返回:

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

getTypeInference

public TypeInference getTypeInference(DataTypeFactory typeFactory)

从类复制的说明: UserDefinedFunction

Returns the logic for performing type inference of a call to this function definition.

The type inference process is responsible for inferring unknown types of input arguments, validating input arguments, and producing result types. The type inference process happens independent of a function body. The output of the type inference is used to search for a corresponding runtime implementation.

Instances of type inference can be created by using TypeInference.newBuilder().

See BuiltInFunctionDefinitions for concrete usage examples.

The type inference for user-defined functions is automatically extracted using reflection. It does this by analyzing implementation methods such as eval() or accumulate() and the generic parameters of a function class if present. If the reflective information is not sufficient, it can be supported and enriched with DataTypeHint and FunctionHint annotations.

Note: Overriding this method is only recommended for advanced users. If a custom type inference is specified, it is the responsibility of the implementer to make sure that the output of the type inference process matches with the implementation method:

The implementation method must comply with each DataType.getConversionClass() returned by the type inference. For example, if DataTypes.TIMESTAMP(3).bridgedTo(java.sql.Timestamp.class) is an expected argument type, the method must accept a call eval(java.sql.Timestamp).

Regular Java calling semantics (including type widening and autoboxing) are applied when calling an implementation method which means that the signature can be eval(java.lang.Object).

The runtime will take care of converting the data to the data format specified by the DataType.getConversionClass() coming from the type inference logic.

指定者:

getTypeInference 在接口中 FunctionDefinition

覆盖:

getTypeInference 在类中 TableAggregateFunction

toString

public String toString()

从类复制的说明: UserDefinedFunction

Returns the name of the UDF that is used for plan explanation and logging.

覆盖:

toString 在类中 UserDefinedFunction