Bug 124444 Preview attached file in pdf will display nothing.
Description: Preview attached file in pdf will display nothing. Steps to reproduce: 1. Preview attached design file in pdf Expected result: Report content shows Actual result: Wait for 10 minutes but nothing showed at all
engine/org.eclipse.birt.report.engine/src/org/eclipse/birt/report/engine/data/IDataEngine.java
IResultSet execute(IBaseQueryDefinition query);
	
	/**
	 * close the IResultSet of the last executing operator
	 */
	void close();
	
	/**
	 * shut down the data engine
	 */
	void shutdown();
	
	/**
	 * evaluate an expression by data engine. Data engine may inturn calls Rhino
	 * 
	 * @param expr
	 *            the data engine expression wrapped in
	 *            <code>IBaseExpression</code>
	 * @return the evaluated result for the data engine expression
	 */
	Object evaluate(IBaseExpression expr);
	
	/**
	 * return the DTE's data engine.
	 * 
	 * @return retuan a dataEngine of DTE.
	 */
	DataEngine getDataEngine();
}