This document discusses open data and the challenges associated with aggregating and using open data from various sources. It notes that open data comes from sources like government records on cadastre, transport, population, energy, statistics, budgets, education, crime, and health. It raises questions about whether the data is updated, whether access could provide economic gains, and whether the honesty of actors can be assumed. It also discusses risks related to the reliability and objectivity of aggregated data from multiple sources used by aggregators. Finally, it presents SAP products that could be used in open data workflows including HANA for rapid data access and ByDesign for mashing up open and internal data.