Package org.apache.vxquery.compiler.rewriter.rules.algebricksalternatives

Class ExtractFunctionsFromJoinConditionRule

java.lang.Object

org.apache.vxquery.compiler.rewriter.rules.algebricksalternatives.ExtractFunctionsFromJoinConditionRule

All Implemented Interfaces:

org.apache.hyracks.algebricks.core.rewriter.base.IAlgebraicRewriteRule

public class ExtractFunctionsFromJoinConditionRule
extends Object
implements org.apache.hyracks.algebricks.core.rewriter.base.IAlgebraicRewriteRule

Factors out function expressions from each comparison function or similarity function in join condition by assigning them to a variables, and replacing the function expressions with references to those variables. Examples: Plan with function expressions in comparison or similarity condition of join expression. Generates one assign operator per extracted function expression.

 Before plan:

   join ( eq( funcX($$1), funcX($$2) ) )

 After plan:

   join (eq($$3,$$4))
   assign [$$4] <- [funcY($$2)]
   assign [$$3] <- [funcX($$1)]
 

Constructor Summary

Constructors

Constructor	Description
ExtractFunctionsFromJoinConditionRule()

Method Summary

Modifier and Type	Method	Description
boolean	rewritePost(org.apache.commons.lang3.mutable.Mutable<org.apache.hyracks.algebricks.core.algebra.base.ILogicalOperator> opRef, org.apache.hyracks.algebricks.core.algebra.base.IOptimizationContext context)
boolean	rewritePre(org.apache.commons.lang3.mutable.Mutable<org.apache.hyracks.algebricks.core.algebra.base.ILogicalOperator> opRef, org.apache.hyracks.algebricks.core.algebra.base.IOptimizationContext context)

Methods inherited from class java.lang.Object

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

Constructor Detail

ExtractFunctionsFromJoinConditionRule

public ExtractFunctionsFromJoinConditionRule()

Method Detail

rewritePre

public boolean rewritePre(org.apache.commons.lang3.mutable.Mutable<org.apache.hyracks.algebricks.core.algebra.base.ILogicalOperator> opRef,
                          org.apache.hyracks.algebricks.core.algebra.base.IOptimizationContext context)
                   throws org.apache.hyracks.algebricks.common.exceptions.AlgebricksException

Specified by:

rewritePre in interface org.apache.hyracks.algebricks.core.rewriter.base.IAlgebraicRewriteRule

Throws:

org.apache.hyracks.algebricks.common.exceptions.AlgebricksException

rewritePost

public boolean rewritePost(org.apache.commons.lang3.mutable.Mutable<org.apache.hyracks.algebricks.core.algebra.base.ILogicalOperator> opRef,
                           org.apache.hyracks.algebricks.core.algebra.base.IOptimizationContext context)
                    throws org.apache.hyracks.algebricks.common.exceptions.AlgebricksException

Specified by:

rewritePost in interface org.apache.hyracks.algebricks.core.rewriter.base.IAlgebraicRewriteRule

Throws:

org.apache.hyracks.algebricks.common.exceptions.AlgebricksException