com.lucidera.lcs
Class LcsTableProjectionRule

java.lang.Object
  org.eigenbase.relopt.RelOptRule
      net.sf.farrago.namespace.impl.MedAbstractFennelProjectionRule
          com.lucidera.lcs.LcsTableProjectionRule

public class LcsTableProjectionRule
extends MedAbstractFennelProjectionRule

LcsTableProjectionRule implements the rule for pushing a Projection into a LcsRowScanRel.

Version:

$Id: //open/dev/farrago/src/com/lucidera/lcs/LcsTableProjectionRule.java#23 $

Author:

Zelaine Fong

Field Summary

static LcsTableProjectionRule

instance

Fields inherited from class org.eigenbase.relopt.RelOptRule

ANY, description, operands

Constructor Summary

private

LcsTableProjectionRule() Creates a LcsTableProjectionRule.

Method Summary

protected Integer	mapProjCol(RexNode exp, List<String> origFieldName, RelDataType rowType) Maps a projection expression to its underlying field reference.
void	onMatch(RelOptRuleCall call) Receives notification about a rule match.

Methods inherited from class net.sf.farrago.namespace.impl.MedAbstractFennelProjectionRule

createNewRelNode, createProjectionList, getOutConvention, mapFieldRef

Methods inherited from class org.eigenbase.relopt.RelOptRule

convert, equals, equals, getOperand, getOperands, getOutTrait, hashCode, matches, mergeTraitsAndConvert, mergeTraitsAndConvert, toString

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

instance

public static final LcsTableProjectionRule instance

Constructor Detail

LcsTableProjectionRule

private LcsTableProjectionRule()

Creates a LcsTableProjectionRule.

Method Detail

onMatch

public void onMatch(RelOptRuleCall call)

Description copied from class: RelOptRule

Receives notification about a rule match. At the time that this method is called, call.rels holds the set of relational expressions which match the operands to the rule; call.rels[0] is the root expression.

Typically a rule would check that the nodes are valid matches, creates a new expression, then calls back RelOptRuleCall.transformTo(org.eigenbase.rel.RelNode) to register the expression.

Specified by:

onMatch in class MedAbstractFennelProjectionRule

Parameters:

call - Rule call

See Also:

RelOptRule.matches(RelOptRuleCall)

mapProjCol

protected Integer mapProjCol(RexNode exp,
                             List<String> origFieldName,
                             RelDataType rowType)

Maps a projection expression to its underlying field reference. Also handles special columns, mapping them to their special column ids.

Overrides:

mapProjCol in class MedAbstractFennelProjectionRule

Parameters:

exp - expression to be mapped

origFieldName - returns field name corresponding to the field reference

rowType - row from which the field reference originated

Returns:

ordinal representing the projection element