Class FilterRel

  extended by org.eigenbase.rel.AbstractRelNode
      extended by org.eigenbase.rel.SingleRel
          extended by org.eigenbase.rel.FilterRelBase
              extended by org.eigenbase.rel.FilterRel
All Implemented Interfaces:
Cloneable, RelNode

public final class FilterRel
extends FilterRelBase

A FilterRel is a relational expression which iterates over its input, and returns elements for which condition evaluates to true.

Field Summary
Fields inherited from class org.eigenbase.rel.AbstractRelNode
digest, id, nextId, rowType, traits
Fields inherited from interface org.eigenbase.rel.RelNode
Constructor Summary
FilterRel(RelOptCluster cluster, RelNode child, RexNode condition)
          Creates a filter.
Method Summary
 FilterRel clone()
          Clones this RelNode.
Methods inherited from class org.eigenbase.rel.FilterRelBase
computeSelfCost, estimateFilteredRows, estimateFilteredRows, explain, getChildExps, getCondition, getRows
Methods inherited from class org.eigenbase.rel.SingleRel
childrenAccept, deriveRowType, getChild, getInputs, replaceInput
Methods inherited from class org.eigenbase.rel.AbstractRelNode
cloneTraits, collectVariablesSet, collectVariablesUsed, computeDigest, getCluster, getCollationList, getConvention, getCorrelVariable, getDescription, getDigest, getExpectedInputRowType, getId, getInput, getOrCreateCorrelVariable, getQuery, getRelTypeName, getRowType, getTable, getTraits, getVariablesStopped, inheritTraitsFrom, isAccessTo, isDistinct, isValid, onRegister, recomputeDigest, register, registerCorrelVariable, setCorrelVariable, toString
Methods inherited from class java.lang.Object
equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail


public FilterRel(RelOptCluster cluster,
                 RelNode child,
                 RexNode condition)
Creates a filter.

cluster - RelOptCluster this relational expression belongs to
child - input relational expression
condition - boolean expression which determines whether a row is allowed to pass
Method Detail


public FilterRel clone()
Description copied from interface: RelNode
Clones this RelNode.

Traits of the RelNode must be explicitly cloned, using AbstractRelNode.inheritTraitsFrom(AbstractRelNode), as the RelNode may have traits of which it has no knowledge. Example implementation:

     public MyRelNode clone()
         MyRelNode clone = new MyRelNode(...);
         return clone;
N.B.: This method must be overridden whenever an existing, concrete RelNode is extended. Otherwise, calling clone() will produce a differently typed RelNode, resulting in invalid or incorrect query plans.

Specified by:
clone in interface RelNode
Specified by:
clone in class AbstractRelNode
a clone of this RelNode