org.apache.drill.common.expression.fn

Interface FuncHolder

All Known Implementing Classes:

AbstractFuncHolder, DrillComplexWriterAggFuncHolder, DrillComplexWriterFuncHolder, DrillFuncHolder, DrillSimpleFuncHolder, HiveFuncHolder

public interface FuncHolder

Definition of a function as presented to code generation. Represents the common denominator between Drill and Hive functions.

Method Summary

Modifier and Type	Method and Description
FunctionHolderExpression	getExpr(String name, List<LogicalExpression> args, ExpressionPosition pos) Return a reference to this function given a function alias and a list of actual arguments.
int	getParamCount() Number of defined input parameters.
TypeProtos.MajorType	getParamMajorType(int i) Drill SQL type of an input parameter.
boolean	isComplexWriterFuncHolder() Checks that the current function holder stores output value using field writer instead of vector holder.
boolean	isNested()

Method Detail

isNested

boolean isNested()

getExpr

FunctionHolderExpression getExpr(String name,
                                 List<LogicalExpression> args,
                                 ExpressionPosition pos)

Return a reference to this function given a function alias and a list of actual arguments.

Parameters:

name - alias used in this specific call

args - expressions of the actual function arguments

pos -

Returns:

an expression that holds the function definition (this object), actual parameters and related information

getParamCount

int getParamCount()

Number of defined input parameters.

getParamMajorType

TypeProtos.MajorType getParamMajorType(int i)

Drill SQL type of an input parameter.

isComplexWriterFuncHolder

boolean isComplexWriterFuncHolder()

Checks that the current function holder stores output value using field writer instead of vector holder.

Returns:

true if current function holder uses field writer to store the output value