Accessing Data Federations with CVMFS

Interactive example-driven integration and reconciliation for accessing database federations

The integration of heterogeneous databases affects two main problems: schema integration and instance integration. At both levels a mapping from local elements to global elements is specified and various conflicts caused by the heterogeneity of the sources have to be resolved. For the detection and resolution of instance-level conflicts we propose an interactive, example-driven approach. The ba...

Modeling Data Federations in ORM

Two major problems in constructing data federations (for example, data warehouses and database federations) concern achieving and maintaining consistency and a uniform representation of the data on the global level of the federation. The first step in creating uniform representations of data is known as data extraction, whereas data reconciliation is concerned with resolving data inconsistencie...

Accessing Eurostat Data

Accessing Data in Block-Compressed Data Warehouses

The large size of most data warehouses (typically hundreds of gigabytes to terabytes), which results in non-trivial storage costs, makes compression techniques attractive for warehousing environments. In particular, block-level compression (as opposed to attribute or record level schemes) has been shown to achieve the greatest reductions in storage size for databases. A key issue is how to quic...

Accessing Data while Preserving Privacy

As organizations struggle with vast amounts of data, outsourcing sensitive data to third parties becomes a necessity. To protect the data, various cryptographic techniques are used in outsourced database systems to ensure data privacy, while allowing efficient querying. Recent attacks on such systems (e.g., [37, 30]) demonstrate that outsourced database systems must trade-off efficiency and pri...