Bug 182061 Data engine changes to support result set sharing
data/org.eclipse.birt.data/src/org/eclipse/birt/data/engine/api/IBaseQueryDefinition.java
/**
	 * Indicates if the report will use the detail rows. Allows the data
	 * engine to optimize the query if the details are not used.
	 * 
	 * @return true if the detail rows are used, false if not used
	 */
	public boolean usesDetails( );
	
	/**
	 * Returns the parent query. The parent query is the outer query which encloses
	 * this query.
	 */
	public IBaseQueryDefinition getParentQuery(); 
	
	/**
	 * Gets the maximum number of detail rows that can be retrieved by this query
	 * @return Maximum number of rows. If 0, there is no limit on how many rows this query can retrieve.
	 */
	public int getMaxRows( );
	
	/**
	 * Gets the expressions that needs to be available at the group/list, as an
	 * Map of bound colum name to {@link org.eclipse.birt.data.engine.api.IBaseExpression} objects.
	 * 
	 * @return
	 */
	public Map getResultSetExpressions( );
}