/*******************************************************************************
 * Copyright (c) 2004, 2005 Actuate Corporation.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *  Actuate Corporation  - initial API and implementation
 *******************************************************************************/
package org.eclipse.birt.data.engine.api.aggregation;

/**
 * All multipass aggregations must implement this interface.
 */
public abstract class Aggregation implements IAggregation
{
	/**
	 * Returns the number of passes over the data series 
	 * that the accumulator of this aggregate requires. For SUMMARY aggregates,
	 * the accumulator returns a value after all passes are complete. For 
	 * RUNNING aggregates, the accumulator returns data in the last pass.
	 * @return
	 */
	public int getNumberOfPasses()	
	{
		return 1;
	}
}
