Efficient top-k document retrieval with two-level indexes

This thesis focuses on top-k document retrieval. The study of such query evaluation method is motivated by a large number of application domains. The efficiency of the evaluation process in particularly relevant due to the rapid growth of Big Data. The basic problem has been recognised by researchers and has motivated a lot of work on optimisation techniques. A new algorithm based on a two-level approach is proposed and compared to the state-of-the-art