org.objectweb.medor.optim.rdb
Class GroupSameDBRule

java.lang.Object
  org.objectweb.medor.optim.lib.BasicRule
      org.objectweb.medor.optim.rdb.GroupSameDBRule

All Implemented Interfaces:

RewriteRule

public class GroupSameDBRule

extends BasicRule

implements RewriteRule

This class groups together as a single RbdExpQueryLeaf the RdbQueryLeaves working on the same data store. TODO: Known limitation : This rule does not reorganize a QueryTree Another rule should be developed to put close together leaves working on the same data store.

Nested Class Summary

protected static class	GroupSameDBRule.RdbQuery The RdbQuery class represents the result of rewriting a QueryTree.
protected static class	GroupSameDBRule.SplitQueries This class represents the result of splitting the children of a given QueryTree qt in presence of MemberOf operators in qt's query filter.

Nested classes inherited from class org.objectweb.medor.optim.lib.BasicRule

BasicRule.ModifiedExpression

Field Summary

Fields inherited from class org.objectweb.medor.optim.lib.BasicRule

debug, log

Constructor Summary

GroupSameDBRule()

Method Summary

protected GroupSameDBRule.SplitQueries	recurseSplit(GroupSameDBRule.SplitQueries split, Expression e) Performs the actual work of splitting a QueryTree starting from its expression.
QueryTree	rewrite(QueryTree qt, QueryNode parent) Implementation of the RewriteRule interface.

Methods inherited from class org.objectweb.medor.optim.lib.BasicRule

replaceUsage, rewrite

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface org.objectweb.medor.optim.api.RewriteRule

rewrite

Constructor Detail

GroupSameDBRule

public GroupSameDBRule()

Method Detail

rewrite

public QueryTree rewrite(QueryTree qt,
                         QueryNode parent)
                  throws MedorException

Implementation of the RewriteRule interface.

It groups together the RdbQueryLeaves if they are on the same data store.

Specified by:

rewrite in interface RewriteRule

Parameters:

qt - the QueryTree to be rewritten by this rule.

parent - the parent QueryNode for which modification of propagated field, if they are replaced in the qt, should be done.

Returns:

the rewritten QueryTree

Throws:

MedorException - if all RdbQueryLeaves are not on the same data store.

See Also:

RewriteRule

recurseSplit

protected GroupSameDBRule.SplitQueries recurseSplit(GroupSameDBRule.SplitQueries split,
                                                    Expression e)

Performs the actual work of splitting a QueryTree starting from its expression.

Parameters:

split - the input SplitQueries object

e - the Expression from which to build the SplitQueries

Returns:

the SplitQueries object constructed from the Expression

See Also:

GroupSameDBRule.SplitQueries