Towards Query Pricing on Incomplete Data

Private Key based query on encrypted data

Nowadays, users of information systems have inclination to use a central server to decrease data transferring and maintenance costs. Since such a system is not so trustworthy, users' data usually upkeeps encrypted. However, encryption is not a nostrum for security problems and cannot guarantee the data security. In other words, there are some techniques that can endanger security of encrypted d...

Image Reconstruction from Incomplete Data

Data exchange: query answering for incomplete data sources

Data exchange is the problem of transforming data structured under a schema, called the source schema, into data structured under another schema, called the target schema. Existing work on data exchange considers settings where the source instance does not contain incomplete information. In this paper we study semantics and address algorithmic issues for data exchange settings where the source ...

Image Reconstruction from Incomplete Data

Towards Efficient SPARQL Query Processing on RDF Data

Efficient support for querying large-scale RDF triples plays an important role in Semantic Web data management. This paper proposes an efficient RDF query engine to evaluate SPARQL queries, where the inverted index structure is employed for indexing RDF triples. We first design and implement a set of operators on the inverted index for query optimization and evaluation. Then we propose a main-t...