net.sf.saffron.oj.rel
Class JavaOneRowRel

java.lang.Object
  |
  +--net.sf.saffron.rel.SaffronRel
        |
        +--net.sf.saffron.rel.OneRowRel
              |
              +--net.sf.saffron.oj.rel.JavaOneRowRel

All Implemented Interfaces:

JavaRel

public class JavaOneRowRel

extends OneRowRel

implements JavaRel

JavaOneRowRel implements OneRowRel inline.

Field Summary

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

cluster, digest, id, rowType

Constructor Summary

JavaOneRowRel(VolcanoCluster cluster)

Method Summary

Object	clone()
CallingConvention	getConvention() Returns a value from CallingConvention.
Object	implement(RelImplementor implementor, int ordinal) Create a plan for this expression according to a calling convention.
Expression	implementSelf(RelImplementor implementor) Returns a Java expression which yields the current row of this relational expression.

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

computeSelfCost, deriveRowType

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

childrenAccept, computeDigest, explain, getChildExps, getCluster, getCorrelVariable, getId, getInput, getInputs, getOrCreateCorrelVariable, getQualifier, getQuery, getRelTypeName, getRows, getRowType, getTable, getVariablesStopped, implementFieldAccess, isAccessTo, isDistinct, onRegister, recomputeDigest, register, registerCorrelVariable, replaceInput, setCorrelVariable, toString

Methods inherited from class java.lang.Object

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

Constructor Detail

JavaOneRowRel

public JavaOneRowRel(VolcanoCluster cluster)

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 OneRowRel

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.

implementSelf

public Expression implementSelf(RelImplementor implementor)

Description copied from interface: JavaRel

Returns a Java expression which yields the current row of this relational expression. This method is called by the RelImplementor the first time a piece of Java code wants to refer to this relation. The implementor then uses this expression to initialize a variable.

If no code needs to refer to this relation, then the expression is never generated. This prevents generating useless code like

Dummy_12f614.Ojp_1 oj_var8 = new Dummy_12f614.Ojp_1();

.

If a relational expression has one input relational expression which has the same row type, you may be able to share its variable. Call Implementor#bind(Rel,Rel) to do this.

Specified by:

implementSelf in interface JavaRel

See Also:

RelImplementor.bind(SaffronRel,SaffronRel)