org.eigenbase.rel
Class ProjectRelBase

java.lang.Object
  org.eigenbase.rel.AbstractRelNode
      org.eigenbase.rel.SingleRel
          org.eigenbase.rel.ProjectRelBase

All Implemented Interfaces:

Cloneable, RelNode

Direct Known Subclasses:

ProjectRel

public abstract class ProjectRelBase
extends SingleRel

ProjectRelBase is an abstract base class for implementations of ProjectRel.

Since:

March, 2004

Version:

$Id: //open/dev/farrago/src/org/eigenbase/rel/ProjectRelBase.java#23 $

Author:

jhyde

Nested Class Summary

private static class	ProjectRelBase.Checker Visitor which walks over a program and checks validity.
static interface	ProjectRelBase.Flags

Field Summary

private List<RelCollation>	collationList
protected RexNode[]	exps
protected int	flags Values defined in ProjectRelBase.Flags.

Fields inherited from class org.eigenbase.rel.AbstractRelNode

digest, id, nextId, rowType, traits

Fields inherited from interface org.eigenbase.rel.RelNode

emptyArray

Constructor Summary

protected

ProjectRelBase(RelOptCluster cluster, RelTraitSet traits, RelNode child, RexNode[] exps, RelDataType rowType, int flags, List<RelCollation> collationList) Creates a Project.

Method Summary

RelOptCost	computeSelfCost(RelOptPlanner planner) Returns the cost of this plan (not including children).
void	explain(RelOptPlanWriter pw)
RexNode[]	getChildExps() Returns an array of this relational expression's child expressions (not including the inputs returned by RelNode.getInputs().
List<RelCollation>	getCollationList() Returns a description of the physical ordering (or orderings) of this relational expression.
int	getFlags()
RexNode[]	getProjectExps() Returns the project expressions.
JavaRel	implementFieldAccess(JavaRelImplementor implementor, String fieldName) Burrows into a synthetic record and returns the underlying relation which provides the field called fieldName.
boolean	isBoxed()
boolean	isValid(boolean fail) Returns whether this relational expression is valid.

Methods inherited from class org.eigenbase.rel.SingleRel

childrenAccept, deriveRowType, getChild, getInputs, getRows, replaceInput

Methods inherited from class org.eigenbase.rel.AbstractRelNode

clone, cloneTraits, collectVariablesSet, collectVariablesUsed, computeDigest, getCluster, getConvention, getCorrelVariable, getDescription, getDigest, getExpectedInputRowType, getId, getInput, getOrCreateCorrelVariable, getQuery, getRelTypeName, getRowType, getTable, getTraits, getVariablesStopped, inheritTraitsFrom, isAccessTo, isDistinct, onRegister, recomputeDigest, register, registerCorrelVariable, setCorrelVariable, toString

Methods inherited from class java.lang.Object

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

Field Detail

exps

protected RexNode[] exps

flags

protected int flags

Values defined in ProjectRelBase.Flags.

collationList

private final List<RelCollation> collationList

Constructor Detail

ProjectRelBase

protected ProjectRelBase(RelOptCluster cluster,
                         RelTraitSet traits,
                         RelNode child,
                         RexNode[] exps,
                         RelDataType rowType,
                         int flags,
                         List<RelCollation> collationList)

Creates a Project.

Parameters:

cluster - Cluster this relational expression belongs to

traits - traits of this rel

child - input relational expression

exps - set of expressions for the input columns

rowType - output row type

flags - values as in ProjectRelBase.Flags

collationList - List of sort keys

Method Detail

getCollationList

public List<RelCollation> getCollationList()

Description copied from interface: RelNode

Returns a description of the physical ordering (or orderings) of this relational expression.

Specified by:

getCollationList in interface RelNode

Overrides:

getCollationList in class AbstractRelNode

isBoxed

public boolean isBoxed()

getChildExps

public RexNode[] getChildExps()

Description copied from interface: RelNode

Returns an array of this relational expression's child expressions (not including the inputs returned by RelNode.getInputs(). If there are no child expressions, returns an empty array, not null.

Specified by:

getChildExps in interface RelNode

Overrides:

getChildExps in class AbstractRelNode

getProjectExps

public RexNode[] getProjectExps()

Returns the project expressions.

getFlags

public int getFlags()

isValid

public boolean isValid(boolean fail)

Description copied from interface: RelNode

Returns whether this relational expression is valid.

If assertions are enabled, this method is typically called with fail = true, as follows:

assert rel.isValid(true)

This signals that the method can throw an AssertionError if it is not valid.

Specified by:

isValid in interface RelNode

Overrides:

isValid in class AbstractRelNode

Parameters:

fail - Whether to fail if invalid

Returns:

Whether relational expression is valid

computeSelfCost

public RelOptCost computeSelfCost(RelOptPlanner planner)

Description copied from interface: RelNode

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

NOTE jvs 29-Mar-2006: Don't call this method directly. Instead, use RelMetadataQuery.getNonCumulativeCost(org.eigenbase.rel.RelNode), which gives plugins a chance to override the rel's default ideas about cost.

Specified by:

computeSelfCost in interface RelNode

Overrides:

computeSelfCost in class AbstractRelNode

explain

public void explain(RelOptPlanWriter pw)

Specified by:

explain in interface RelNode

Overrides:

explain in class SingleRel

implementFieldAccess

public JavaRel implementFieldAccess(JavaRelImplementor implementor,
                                    String fieldName)

Burrows into a synthetic record and returns the underlying relation which provides the field called fieldName.