saffron.rel.java
Class ExistsConverter

java.lang.Object
  |
  +--saffron.rel.Rel
        |
        +--saffron.rel.SingleRel
              |
              +--saffron.rel.convert.Converter
                    |
                    +--saffron.rel.java.ExistsConverter

public class ExistsConverter

extends Converter

An ExistsConverter converts a relational expression node (Rel) to CallingConvention.EXISTS_ORDINAL calling convention: an expression which yields true if the relation returns at least one row.

Nested Class Summary

Nested classes inherited from class saffron.rel.Rel

Field Summary

Fields inherited from class saffron.rel.convert.Converter

inConvention

Fields inherited from class saffron.rel.SingleRel

child

Fields inherited from class saffron.rel.Rel

cluster, digest, id, rowType

Constructor Summary

ExistsConverter(Cluster cluster, Rel child)

Method Summary

Object	clone()
CallingConvention	getConvention() Returns a value from CallingConvention.
Object	implement(Implementor implementor, int ordinal) Create a plan for this expression according to a calling convention.
private Object	implementArray(Implementor implementor, int ordinal)
private Object	implementCollection(Implementor implementor, int ordinal)
private Object	implementEnumeration(Implementor implementor, int ordinal)
private Object	implementHashtable(Implementor implementor, int ordinal)
private Object	implementIterator(Implementor implementor, int ordinal)
private Object	implementJava(Implementor implementor, int ordinal)
private Object	implementMap(Implementor implementor, int ordinal)
static void	init(Planner planner)

Methods inherited from class saffron.rel.convert.Converter

computeSelfCost

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, isDistinct, onRegister, recomputeDigest, register, registerCorelVariable, setCorelVariable, toString

Methods inherited from class java.lang.Object

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

Constructor Detail

ExistsConverter

public ExistsConverter(Cluster cluster,
                       Rel child)

Method Detail

clone

public Object clone()

Specified by:

clone in class Rel

getConvention

public CallingConvention getConvention()

Description copied from class: Rel

Returns a value from CallingConvention.

Overrides:

getConvention in class Rel

init

public static void init(Planner planner)

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 Converter

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.

implementJava

private Object implementJava(Implementor implementor,
                             int ordinal)

implementArray

private Object implementArray(Implementor implementor,
                              int ordinal)

implementIterator

private Object implementIterator(Implementor implementor,
                                 int ordinal)

implementMap

private Object implementMap(Implementor implementor,
                            int ordinal)

implementHashtable

private Object implementHashtable(Implementor implementor,
                                  int ordinal)

implementEnumeration

private Object implementEnumeration(Implementor implementor,
                                    int ordinal)

implementCollection

private Object implementCollection(Implementor implementor,
                                   int ordinal)