org.apache.directory.server.xdbm.search
Interface Optimizer

All Known Implementing Classes:
DefaultOptimizer, NoOpOptimizer

public interface Optimizer

An optimizer applies heuristics to determine best execution path to a search filter based on scan counts within database indices. It annotates the nodes of an expression subtree by setting a "count" key in the node. Its goal is to annotate nodes with counts to indicate which nodes to iterate over thereby minimizing the number cycles in a search. The SearchEngine relies on these count markers to determine the appropriate path.

Version:
$Rev: 656041 $
Author:
Apache Directory Project

Method Summary
 java.lang.Long annotate(org.apache.directory.shared.ldap.filter.ExprNode node)
          Annotates the expression node tree for optimized traversal metrics.
 

Method Detail

annotate

java.lang.Long annotate(org.apache.directory.shared.ldap.filter.ExprNode node)
                        throws java.lang.Exception
Annotates the expression node tree for optimized traversal metrics.

Parameters:
node - the root of the expression node tree
Throws:
java.lang.Exception - if there are failures while optimizing


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