Bug 182061 Data engine changes to support result set sharing
data/org.eclipse.birt.data/src/org/eclipse/birt/data/engine/impl/PreparedQuery.java
this.subQueryDefnMap = new HashMap( );
		this.aggrTable = new AggregateTable( this.session.getSharedScope( ),
				baseQueryDefn.getGroups( ) );
		logger.fine( "Start to prepare a PreparedQuery." );
		prepare( );
		logger.fine( "Finished preparing the PreparedQuery." );
	}
	
	/**
	 * @throws DataException
	 */
	private void prepare( ) throws DataException
	{
	    
		Context cx = Context.enter();		
		try
		{
			
			
			
						
			if ( this.baseQueryDefn.getResultSetExpressions( ) != null
					&& this.baseQueryDefn.getResultSetExpressions( ).size( ) > 0 )
			{
				this.expressionCompiler.setDataSetMode( false );
			}
			
			List groups = baseQueryDefn.getGroups( );
			Set groupNameSet = new HashSet( );
			IGroupDefinition group;