saffron.rel.java
Class JavaExists

java.lang.Object
  |
  +--saffron.rel.Rel
        |
        +--saffron.rel.SingleRel
              |
              +--saffron.rel.Distinct
                    |
                    +--saffron.rel.java.JavaExists

public class JavaExists

extends Distinct

JavaExists implements Distinct inline for the special case that the input relation has zero columns.

Nested Class Summary

Nested classes inherited from class saffron.rel.Distinct

Nested classes inherited from class saffron.rel.Rel

Field Summary

Fields inherited from class saffron.rel.SingleRel

child

Fields inherited from class saffron.rel.Rel

cluster, digest, id, rowType

Constructor Summary

JavaExists(Cluster cluster, Rel child)

Method Summary

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

Methods inherited from class saffron.rel.Distinct

isDistinct, register

Methods inherited from class saffron.rel.SingleRel

childrenAccept, deriveRowType, explain, getInputs, replaceInput

Methods inherited from class saffron.rel.Rel

computeDigest, getChildExps, getCluster, getCorelVariable, getEnvironment, getId, getInput, getOrCreateCorelVariable, getParentEnv, getQualifier, getQuery, getRelTypeName, getRows, getRowType, getTable, getType, getVariablesStopped, implementExp, implementExps, implementFieldAccess, implementSelf, isAccessTo, onRegister, recomputeDigest, registerCorelVariable, setCorelVariable, toString

Methods inherited from class java.lang.Object

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

Constructor Detail

JavaExists

public JavaExists(Cluster cluster,
                  Rel child)

Method Detail

clone

public Object clone()

Overrides:

clone in class Distinct

getConvention

public CallingConvention getConvention()

Description copied from class: Rel

Returns a value from CallingConvention.

Overrides:

getConvention in class Rel

computeSelfCost

public Cost computeSelfCost(Planner planner)

Description copied from class: Rel

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

Overrides:

computeSelfCost in class Distinct

implement

public Object implement(Implementor implementor,
                        int ordinal)

Description copied from class: Rel

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

Overrides:

implement in class Rel

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.