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

Interface PhysicalOperator

All Known Subinterfaces:

BinaryPhysicalOp, BinaryPhysicalOpForLogicalOp, NaryPhysicalOp, NaryPhysicalOpForLogicalOp, NullaryPhysicalOp, NullaryPhysicalOpForLogicalOp, PhysicalOperatorForLogicalOperator, UnaryPhysicalOp, UnaryPhysicalOpForLogicalOp

All Known Implementing Classes:

BaseForPhysicalOpBinaryJoin, BaseForPhysicalOpMultiwayJoin, BaseForPhysicalOpMultiwayLeftJoin, BaseForPhysicalOps, BaseForPhysicalOpSingleInputJoin, PhysicalOpBinaryUnion, PhysicalOpBindJoin, PhysicalOpBindJoinWithFILTER, PhysicalOpBindJoinWithUNION, PhysicalOpBindJoinWithVALUES, PhysicalOpFilter, PhysicalOpGlobalToLocal, PhysicalOpHashJoin, PhysicalOpHashRJoin, PhysicalOpIndexNestedLoopsJoin, PhysicalOpLocalToGlobal, PhysicalOpMultiwayUnion, PhysicalOpNaiveNestedLoopsJoin, PhysicalOpParallelMultiLeftJoin, PhysicalOpRequest, PhysicalOpSymmetricHashJoin

public interface PhysicalOperator

This is the top-level interface for all types of physical operators of HeFQUIN, where a physical operator is an element in a (physical) query execution plan and is associated with a concrete algorithm that produces a result (in HeFQUIN, this would be in the form of a sequence of solution mappings) by consuming such results produced by the sub-plans under the current operator. The function can be used to obtain an {@link ExecutableOperator} that provides an implementation of the algorithm associated with the physical operator in a form that can be plugged directly into the query execution framework of HeFQUIN.

Method Summary

Modifier and Type	Method	Description
ExecutableOperator	createExecOp(boolean collectExceptions, ExpectedVariables... inputVars)	Creates and returns the executable operator to be used for this physical operator.
ExpectedVariables	getExpectedVariables(ExpectedVariables... inputVars)	Returns the variables that can be expected in the solution mappings produced by this operator if the input(s) to this operator contain solutions mappings with the given set(s) of variables.
int	getID()	Returns an identifier of this operator, which should be unique for all the operators within the same plan (no matter what type of operator they are).
void	visit(PhysicalPlanVisitor visitor)

Method Details

createExecOp

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

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).

getExpectedVariables

ExpectedVariables getExpectedVariables(ExpectedVariables... inputVars)

Returns the variables that can be expected in the solution mappings produced by this operator if the input(s) to this operator contain solutions mappings with the given set(s) of variables. The number of ExpectedVariables objects passed 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).

getID

int getID()

Returns an identifier of this operator, which should be unique for all the operators within the same plan (no matter what type of operator they are).

visit

void visit(PhysicalPlanVisitor visitor)