com.lucidera.lcs
Class LcsIndexOnlyAccessRule

java.lang.Object
  org.eigenbase.relopt.RelOptRule
      com.lucidera.lcs.LcsIndexOnlyAccessRule

public class LcsIndexOnlyAccessRule
extends RelOptRule

A rule for converting an LcsRowScanRel(LcsIndexSearchRel) to an LcsIndexOnlyScanRel. The conversion can be applied if an index scan can satisfy the columns of a row scan.

Version:

$Id: //open/dev/farrago/src/com/lucidera/lcs/LcsIndexOnlyAccessRule.java#11 $

Author:

John Pham

Field Summary

static LcsIndexOnlyAccessRule	instanceMerge
static LcsIndexOnlyAccessRule	instanceSearch The singletons

Fields inherited from class org.eigenbase.relopt.RelOptRule

ANY, description, operands

Constructor Summary

LcsIndexOnlyAccessRule(RelOptRuleOperand operand, String id)
Creates an LcsIndexOnlyAccessRule.

Method Summary

CallingConvention	getOutConvention() Returns the calling convention of the result of firing this rule, null if not known.
void	onMatch(RelOptRuleCall call) Receives notification about a rule match.
private boolean	samePrefix(FemLocalIndex a, FemLocalIndex b, int nKeys) Determines whether two indexes have the same prefix, up to a specified number of keys

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

instanceSearch

public static final LcsIndexOnlyAccessRule instanceSearch

The singletons

instanceMerge

public static final LcsIndexOnlyAccessRule instanceMerge

Constructor Detail

LcsIndexOnlyAccessRule

public LcsIndexOnlyAccessRule(RelOptRuleOperand operand,
                              String id)

Creates an LcsIndexOnlyAccessRule.

Parameters:

operand - Root operand, must not be null

id - Description of rule

Method Detail

getOutConvention

public CallingConvention getOutConvention()

Description copied from class: RelOptRule

Returns the calling convention of the result of firing this rule, null if not known.

Overrides:

getOutConvention in class RelOptRule

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 RelOptRule

Parameters:

call - Rule call

See Also:

RelOptRule.matches(RelOptRuleCall)

samePrefix

private boolean samePrefix(FemLocalIndex a,
                           FemLocalIndex b,
                           int nKeys)

Determines whether two indexes have the same prefix, up to a specified number of keys