org.objectweb.medor.optim.api
Interface RewriteRule

All Known Subinterfaces:
LeafRewriteRule
All Known Implementing Classes:
BasicRule, GroupSameDBRule, JormLeafRewriteRule

public interface RewriteRule

This interface describes a rule used by the QueryTransformer. It typically pushes selections, replaces a JORM scan with the corresp. RdbQueryLeaf, groups operations on the same data source if possible (depending on the evaluation capacity of the data source) into a single QueryLeaf, etc.


Method Summary
 QueryTree rewrite(QueryTree qt)
          This method applies a single rule.
 

Method Detail

rewrite

public QueryTree rewrite(QueryTree qt)
                  throws MedorException
This method applies a single rule. It is typically called by the QueryRewriter for applying the entire rewriting process.

Parameters:
qt - the QueryTree to be rewritten
Returns:
the rewritten QueryTree
Throws:
MedorException