Package se.liu.ida.hefquin.engine.queryproc.impl.loptimizer.heuristics

Class PullUpLtgOverJoin

java.lang.Object

se.liu.ida.hefquin.engine.queryproc.impl.loptimizer.heuristics.PullUpLtgOverJoin

All Implemented Interfaces:

HeuristicForLogicalOptimization

public class PullUpLtgOverJoin
extends Object
implements HeuristicForLogicalOptimization

Constructor Summary

Constructors

Constructor	Description
PullUpLtgOverJoin()

Method Summary

Modifier and Type	Method	Description
LogicalPlan	apply(LogicalPlan inputPlan)	Applies this heuristics to the given plan and returns the resulting, potentially rewritten plan.
static boolean	checkIfLtgCanBeExtractedOverJoin(LogicalPlan inputPlan)	Check if l2g operator can be pulled up over join by checking: i) the root operator is a join (binary or multiway), ii) every subplan under this join has an l2g operator as its root, iii) all these l2g operators have the same vocab.mapping, and iv) that vocab.mapping is an "equivalence-only" mapping.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

PullUpLtgOverJoin

public PullUpLtgOverJoin()

Method Details

apply

public LogicalPlan apply(LogicalPlan inputPlan)

Description copied from interface: HeuristicForLogicalOptimization

Applies this heuristics to the given plan and returns the resulting, potentially rewritten plan.

Specified by:

apply in interface HeuristicForLogicalOptimization

checkIfLtgCanBeExtractedOverJoin

public static boolean checkIfLtgCanBeExtractedOverJoin(LogicalPlan inputPlan)

Check if l2g operator can be pulled up over join by checking: i) the root operator is a join (binary or multiway), ii) every subplan under this join has an l2g operator as its root, iii) all these l2g operators have the same vocab.mapping, and iv) that vocab.mapping is an "equivalence-only" mapping.