net.sf.saffron.oj.rel
Class JavaExistsRel

java.lang.Object
  |
  +--net.sf.saffron.rel.SaffronRel
        |
        +--net.sf.saffron.rel.SingleRel
              |
              +--net.sf.saffron.rel.DistinctRel
                    |
                    +--net.sf.saffron.oj.rel.JavaExistsRel

public class JavaExistsRel

extends DistinctRel

JavaExistsRel implements DistinctRel inline for the special case that the input relation has zero columns.

Field Summary

Fields inherited from class net.sf.saffron.rel.SingleRel

child

Fields inherited from class net.sf.saffron.rel.SaffronRel

cluster, digest, id, rowType

Constructor Summary

JavaExistsRel(VolcanoCluster cluster, SaffronRel child)

Method Summary

Object	clone()
PlanCost	computeSelfCost(SaffronPlanner planner) Returns the cost of this plan (not including children).
CallingConvention	getConvention() Returns a value from CallingConvention.
Object	implement(RelImplementor implementor, int ordinal) Create a plan for this expression according to a calling convention.

Methods inherited from class net.sf.saffron.rel.DistinctRel

isDistinct

Methods inherited from class net.sf.saffron.rel.SingleRel

childrenAccept, deriveRowType, explain, getInputs, getRows, replaceInput

Methods inherited from class net.sf.saffron.rel.SaffronRel

computeDigest, getChildExps, getCluster, getCorrelVariable, getId, getInput, getOrCreateCorrelVariable, getQualifier, getQuery, getRelTypeName, getRowType, getTable, getVariablesStopped, implementFieldAccess, isAccessTo, onRegister, recomputeDigest, register, registerCorrelVariable, setCorrelVariable, toString

Methods inherited from class java.lang.Object

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

Constructor Detail

JavaExistsRel

public JavaExistsRel(VolcanoCluster cluster,
                     SaffronRel child)

Method Detail

getConvention

public CallingConvention getConvention()

Description copied from class: SaffronRel

Returns a value from CallingConvention.

Overrides:

getConvention in class SaffronRel

clone

public Object clone()

Overrides:

clone in class DistinctRel

computeSelfCost

public PlanCost computeSelfCost(SaffronPlanner planner)

Description copied from class: SaffronRel

Returns the cost of this plan (not including children). The base implementation throws an error; derived classes should override.

Overrides:

computeSelfCost in class DistinctRel

implement

public Object implement(RelImplementor implementor,
                        int ordinal)

Description copied from class: SaffronRel

Create a plan for this expression according to a calling convention.

Overrides:

implement in class SaffronRel

Parameters:

implementor - implementor

ordinal - indicates our position in the pre-, in- and postfix walk over the tree; ordinal is -1 when called from the parent, and i when called from the i^th child.