Bug 182061 Data engine changes to support result set sharing
data/org.eclipse.birt.data/src/org/eclipse/birt/data/engine/impl/DataEngineImpl.java
else
			dscManager.clearCache( dataSource, dataSet );
	}
	
	/**
	 * Returns the runtime defn of a data source. If data source is not found,
	 * returns null.
	 */
	DataSourceRuntime getDataSourceRuntime( String name )
	{
		return (DataSourceRuntime) dataSources.get( name );
	}
	/**
	 * Returns the design of a data set. If data set is not found, returns null.
	 */
	IBaseDataSetDesign getDataSetDesign( String name )
	{
		return (IBaseDataSetDesign) dataSetDesigns.get( name );
	}
	/**
	 * Verifies the elements of a report query spec
	 * and provides a hint to the query to prepare and optimize 
	 * an execution plan.
	 * The given querySpec could be a ReportQueryDefn 
	 * (raw data transform) spec generated by the factory 
	 * based on static definition found in a report design.
	 * <p> 
	 * This report query spec could be further refined by FPE 
	 * during engine execution after having resolved any related
	 * runtime condition.  This is probably not in BIRT Release 1.