Bug 214196 [Automation][Compatibility]Exception occurs when preview a old crosstab with measure sorting
data/org.eclipse.birt.data/src/org/eclipse/birt/data/engine/impl/DataEngineImpl.java
throw e;
		}
		if ( dataSourcesJSObject == null )
		{
			dataSourcesJSObject = new JSDataSources( this.dataSources );
		}
		return dataSourcesJSObject;
	}
	/*
	 * (non-Javadoc)
	 * @see org.eclipse.birt.data.engine.api.DataEngine#prepare(org.eclipse.birt.data.engine.olap.api.query.ICubeQueryDefinition, java.util.Map)
	 */
	public IPreparedCubeQuery prepare( ICubeQueryDefinition query,
			Map appContext ) throws BirtException
	{
		return new PreparedCubeQuery( query,
				this.session,
				this.context,
				appContext );
	}
	
	/*
	 * (non-Javadoc)
	 * @see org.eclipse.birt.data.engine.api.DataEngine#getCachedDataSetMetaData(org.eclipse.birt.data.engine.api.IBaseDataSourceDesign, org.eclipse.birt.data.engine.api.IBaseDataSetDesign)
	 */
	public IResultMetaData getCachedDataSetMetaData(IBaseDataSourceDesign dataSource, IBaseDataSetDesign dataSet) throws BirtException 
	{
		return this.session.getDataSetCacheManager().getCachedResultMetadata( dataSource, dataSet);
	}
}