The document discusses data virtualization, including what it is, why it is used, when not to use it, the functionality it provides, and its relationship to big data and NoSQL systems. Specifically:
- Data virtualization allows applications to access and manipulate data without knowing its physical location or format.
- It is used to provide a unified view of diverse data sources for business needs like analytics and transactions.
- Data virtualization is not always the best solution and may not be suitable when data needs to be persisted long-term in a data warehouse.
- Potential drawbacks can include increased overhead for governance, change management, and impact on operational systems if not implemented correctly.