FunctionRegistryBase¶

FunctionRegistryBase[T] is an abstraction of function registries for registering functions (that produce a result of type T).

Contract (Subset)¶

lookupFunction¶

lookupFunction(
  name: FunctionIdentifier): Option[ExpressionInfo]

Looks up the ExpressionInfo metadata of a user-defined function by the given name

See SimpleFunctionRegistryBase

Used when:

FunctionRegistryBase is requested to check if a function exists
SessionCatalog is requested to lookupBuiltinOrTempFunction, lookupBuiltinOrTempTableFunction, lookupPersistentFunction

Registering Named User-Defined Function¶

registerFunction(
  name: FunctionIdentifier,
  info: ExpressionInfo,
  builder: Seq[Expression] => T): Unit
registerFunction(
  name: FunctionIdentifier,
  builder: Seq[Expression] => T,
  source: String): Unit // (1)!

A final method that relays to the abstract registerFunction

Registers a user-defined function (written in Python, Scala or Java) under the given name

See:

SimpleFunctionRegistryBase

Used when:

FunctionRegistryBase is requested to createOrReplaceTempFunction
SessionCatalog is requested to registerFunction, reset
SparkSessionExtensions is requested to registerFunctions, registerTableFunctions

Implementations¶

createOrReplaceTempFunction¶

createOrReplaceTempFunction(
  name: String,
  builder: Seq[Expression] => T,
  source: String): Unit

createOrReplaceTempFunction registers a named function (with a FunctionIdentifier for the given name).

source Argument

source	Call Site
`java_udf`	UDFRegistration.register
`python_udf`	UDFRegistration.registerPython
`scala_udf`	UDFRegistration.register

source is used to create an ExpressionInfo for registering a named function.

createOrReplaceTempFunction is used when:

UDFRegistration is requested to register a user-defined function written in Python or Scala