Bug 202038 errors occurred when preview the attached design file.
data/org.eclipse.birt.data/src/org/eclipse/birt/data/engine/executor/transform/pass/ResultSetProcessUtil.java
/**
	 * Build an IResultClass instance excluding temp computed columns.
	 * 
	 * @param meta
	 * @return
	 * @throws DataException
	 */
	private static IResultClass rebuildResultClass( IResultClass meta )
			throws DataException
	{
		List projectedColumns = new ArrayList( );
		for ( int i = 1; i <= meta.getFieldCount( ); i++ )
		{
			if ( !PassUtil.isTemporaryResultSetComputedColumn( meta.getFieldName( i ) ) )
			{
				ResultFieldMetadata field = new ResultFieldMetadata( 0,
						meta.getFieldName( i ),
						meta.getFieldLabel( i ),
						meta.getFieldValueClass( i ),
						meta.getFieldNativeTypeName( i ),
						meta.isCustomField( i ) );
				field.setAlias( meta.getFieldAlias( i ) );
				projectedColumns.add( field );
			}
		}
		IResultClass result = new ResultClass( projectedColumns );
		return result;
	}
}