Package se.liu.ida.hefquin.engine.queryplan.physical

Interface NullaryPhysicalOp

All Superinterfaces:

PhysicalOperator

All Known Subinterfaces:

NullaryPhysicalOpForLogicalOp

All Known Implementing Classes:

PhysicalOpRequest

public interface NullaryPhysicalOp
extends PhysicalOperator

An interface for any type of PhysicalOperator whose algorithm does not consume any input (but produces a sequence of solution mappings as output).

Method Summary

Modifier and Type	Method	Description
NullaryExecutableOp	createExecOp(boolean collectExceptions, ExpectedVariables... inputVars)	Creates and returns the executable operator to be used for this physical operator.

Methods inherited from interface se.liu.ida.hefquin.engine.queryplan.physical.PhysicalOperator

getExpectedVariables, getID, visit

Method Details

createExecOp

NullaryExecutableOp createExecOp(boolean collectExceptions,
 ExpectedVariables... inputVars)

Description copied from interface: PhysicalOperator

Creates and returns the executable operator to be used for this physical operator. The implementation of this method has to create a new ExecutableOperator object each time it is called. The given collectExceptions flag is passed to the executable operator and determines whether that operator collects its exceptions (see ExecutableOperator.getExceptionsCaughtDuringExecution()) or throws them immediately. The number of ExpectedVariables objects passed as arguments to this method must be in line with the degree of this operator (e.g., for a unary operator, exactly one such object must be passed).

Specified by:

createExecOp in interface PhysicalOperator