Class ProjectRel

Direct Known Subclasses:

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
Field Summary
Fields inherited from class net.sf.saffron.rel.ProjectRelBase
exps, fieldNames, flags
Fields inherited from class net.sf.saffron.rel.SingleRel
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


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

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


public Object clone()
Specified by:
clone in class SaffronRel