org.apache.flink.table.functions

类 BuiltInFunctionDefinition

java.lang.Object

org.apache.flink.table.functions.BuiltInFunctionDefinition

所有已实现的接口:

FunctionDefinition, SpecializedFunction

@Internal
public final class BuiltInFunctionDefinition
extends Object
implements SpecializedFunction

Definition of a built-in function. It enables unique identification across different modules by reference equality.

Compared to regular FunctionDefinition, built-in functions have a default name. This default name is used to lookup the function in a catalog during resolution.

Equality is defined by reference equality.

嵌套类概要

嵌套类

限定符和类型	类和说明
static class	BuiltInFunctionDefinition.Builder Builder for fluent definition of built-in functions.

从接口继承的嵌套类/接口 org.apache.flink.table.functions.SpecializedFunction

SpecializedFunction.SpecializedContext

方法概要

限定符和类型	方法和说明
FunctionKind	getKind() Returns the kind of function this definition describes.
String	getName()
Optional<String>	getRuntimeClass()
TypeInference	getTypeInference(DataTypeFactory typeFactory) Returns the logic for performing type inference of a call to this function definition.
boolean	hasRuntimeImplementation()
boolean	isDeterministic() Returns information about the determinism of the function's results.
static BuiltInFunctionDefinition.Builder	newBuilder() Builder for configuring and creating instances of BuiltInFunctionDefinition.
UserDefinedFunction	specialize(SpecializedFunction.SpecializedContext context) Provides a runtime implementation that is specialized for the given call and session.
String	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

getRequirements

方法详细资料

newBuilder

public static BuiltInFunctionDefinition.Builder newBuilder()

Builder for configuring and creating instances of BuiltInFunctionDefinition.

getName

public String getName()

getRuntimeClass

public Optional<String> getRuntimeClass()

hasRuntimeImplementation

public boolean hasRuntimeImplementation()

specialize

public UserDefinedFunction specialize(SpecializedFunction.SpecializedContext context)

从接口复制的说明: SpecializedFunction

Provides a runtime implementation that is specialized for the given call and session.

The method must return an instance of UserDefinedFunction or throw a TableException if the given call is not supported. The returned instance must have the same FunctionDefinition semantics but can have a different FunctionDefinition.getTypeInference(DataTypeFactory) implementation.

指定者:

specialize 在接口中 SpecializedFunction

getKind

public FunctionKind getKind()

从接口复制的说明: FunctionDefinition

Returns the kind of function this definition describes.

指定者:

getKind 在接口中 FunctionDefinition

getTypeInference

public TypeInference getTypeInference(DataTypeFactory typeFactory)

从接口复制的说明: FunctionDefinition

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.

指定者:

getTypeInference 在接口中 FunctionDefinition

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

toString

public String toString()

覆盖:

toString 在类中 Object