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
new OdiResultSetWrapper( populator.getResultIterator( ) ),
						true,
						session );
			}
			this.populator.getExpressionProcessor( )
					.setResultIterator( this.populator.getResultIterator( ) );
			AggrDefnRoundManager factory = new AggrDefnRoundManager( aggrDefns );
			for ( int i = 0; i < factory.getRound( ); i++ )
			{
				AggregationHelper helper = new AggregationHelper( factory.getAggrDefnManager( i ),
						this.populator );
				this.populator.getResultIterator( ).addAggrValueHolder( helper );
			}
		}
	}
	/**
	 * Indicate whether need to pre calculate the aggregations.
	 * @param needGroupFiltering
	 * @param needGroupSorting
	 * @return
	 */
	private boolean needPreCalculateForGroupFilterSort(
			boolean needGroupFiltering, boolean needGroupSorting )
	{
		return needGroupFiltering || needGroupSorting;
	}
	/**
	 * Indicate whether need to do group filtering.
	 * @return
	 */