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

Class EliminateUnnestAggregateSubplanRule

java.lang.Object

org.apache.vxquery.compiler.rewriter.rules.EliminateUnnestAggregateSubplanRule

All Implemented Interfaces:

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

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

The rule searches for unnest followed by subplan with the root operator an aggregate and removes the aggregate subplan.

 Before
 
   %PARENT_PLAN
   UNNEST( $v2 : iterate( $v1 ) )
   SUBPLAN{
     AGGREGATE( $v1 : sequence( %expression ) )
     %NESTED_PLAN
     NESTEDTUPLESOURCE
   }
   %CHILD_PLAN
   
   where %PARENT_PLAN does not use $v1.
    
 After 
 
   %PARENT_PLAN
   UNNEST( $v2 : iterate( $v3 ) )
   ASSIGN( $v3 : %expression )
   %NESTED_PLAN
   %CHILD_PLAN
 

Constructor Summary

Constructors

Constructor	Description
EliminateUnnestAggregateSubplanRule()

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

EliminateUnnestAggregateSubplanRule

public EliminateUnnestAggregateSubplanRule()

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)

Specified by:

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