net.sf.saffron.rel
Class ProjectRel

java.lang.Object
  |
  +--net.sf.saffron.rel.SaffronRel
        |
        +--net.sf.saffron.rel.SingleRel
              |
              +--net.sf.saffron.rel.ProjectRelBase
                    |
                    +--net.sf.saffron.rel.ProjectRel

Direct Known Subclasses:

JavaProjectRel

public class ProjectRel

extends ProjectRelBase

ProjectRel is a relational expression which computes a set of 'select expressions' from its input relational expression.

The result is usually 'boxed' as a record with one named field for each column; if there is precisely one expression, the result may be 'unboxed', and consist of the raw value type.

Nested Class Summary

Nested classes inherited from class net.sf.saffron.rel.ProjectRelBase

ProjectRelBase.Flags

Field Summary

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

exps, fieldNames, flags

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

child

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

cluster, digest, emptyArray, id, nextId, rowType

Constructor Summary

ProjectRel(VolcanoCluster cluster, SaffronRel child, RexNode[] exps, String[] fieldNames, int flags)
Creates a Project.

Method Summary

Object

clone()

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

computeSelfCost, defineTerms, deriveRowType, explain, getChildExps, getFieldNames, getFlags, implementFieldAccess, isBoxed

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

childrenAccept, getInputs, getRows, replaceInput

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

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

Methods inherited from class java.lang.Object

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

Constructor Detail

ProjectRel

public ProjectRel(VolcanoCluster cluster,
                  SaffronRel child,
                  RexNode[] exps,
                  String[] fieldNames,
                  int flags)

Creates a Project.

Parameters:

cluster - VolcanoCluster this relational expression belongs to

child - input relational expression

exps - set of expressions for the input columns

fieldNames - aliases of the expressions

flags - values as in ProjectRelBase.Flags

Method Detail

clone

public Object clone()

Specified by:

clone in class SaffronRel