Bug 206861 The data set cache should handle IOException and the cancel request from customer
The data set data will be saved into disk file in the first query and it will be loaded in the later time. The processing of write disk file may be cancelled by customer request or IOException. Using the data from the bad file will cause error.
data/org.eclipse.birt.data/src/org/eclipse/birt/data/engine/executor/cache/IRowResultSet.java
{
	/**
	 * @return result meta data
	 */
	IResultClass getMetaData( );
	
	/**
	 * Notice the return value of this function is IResultObject. The null value
	 * indicates the cursor exceeds the end of result set.
	 * 
	 * @return next result data
	 * @throws DataException
	 */
	IResultObject next( ) throws DataException;
}