com.lucidera.lcs
Class LcsIndexOnlyAccessRule

java.lang.Object
  extended by org.eigenbase.relopt.RelOptRule
      extended by 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