Bug 201013 [Automation][Regression]Invalid group key column name: _{$TEMP_GROUP_1$} occurs when preview attached report[1102]
data/org.eclipse.birt.data/src/org/eclipse/birt/data/engine/executor/dscache/CandidateQuery.java
/*
	 * @see org.eclipse.birt.data.engine.odi.IQuery#close()
	 */
	public void close( )
	{
		try
		{
			if ( datasetCache != null )
			{
				datasetCache.close( );
				datasetCache = null;
			}
		}
		catch ( DataException e )
		{
			
		}
	}
	
	/**
	 * @return OdaCacheResultSet
	 */
	private DataSetResultCache getOdaCacheResultSet( )
	{
		if ( datasetCache == null )
			datasetCache = new DataSetResultCache( session );
		return datasetCache;
	}
}