@PublicEvolving public abstract class UserDefinedFunction extends Object implements Serializable
Constructor and Description |
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UserDefinedFunction() |
Modifier and Type | Method and Description |
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void |
close()
Tear-down method for user-defined function.
|
String |
functionIdentifier()
Returns a unique, serialized representation for this function.
|
boolean |
isDeterministic()
Returns information about the determinism of the function's results.
|
void |
open(FunctionContext context)
Setup method for user-defined function.
|
String |
toString()
Returns the name of the UDF that is used for plan explain and logging.
|
public final String functionIdentifier()
public void open(FunctionContext context) throws Exception
Exception
public void close() throws Exception
Exception
public boolean isDeterministic()
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 pure functional like
random(), date(), now(), ...
this method must return false
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