IDEAS

The Linked Data Benchmark Council (LDBC) is an EU project that aims to develop industry-strength benchmarks for graph and RDF data management systems. LDBC introduces a so-called "choke-point" based benchmark development, through which experts identify ...

The all-pairs problem is an input-output relationship where each output corresponds to a pair of inputs, and each pair of inputs has a corresponding output. It models similarity joins where no simplification of the search for similar pairs, e.g., ...

Parallel share-nothing architectures are currently used to handle large amounts of data arriving in real-time for processing. The continuous increase on data volume and organization, introduce several limitations to scalability and quality of service (...

Multidimensional data are commonly utilized in many application areas like electronic shopping, cartography and many others. These data structures support various types of queries, e.g. point or range query. The range query retrieves all tuples of a ...

The dynamicity of sensor data sources and publishing real-time sensor data over a generalised infrastructure like the Web pose a new set of integration challenges. Semantic Sensor Networks demand excessive expressivity for efficient formal analysis of ...

In many applications, it is convenient to substitute a large data graph with a smaller homomorphic graph. This paper investigates approaches for summarising massive data graphs. In general, massive data graphs are processed using a shared-nothing ...

Highly efficient query processing on high-dimensional data, while important, is still a challenge nowadays -- as the curse of dimensionality makes efficient solution very difficult. On the other hand, there have been suggestions that it is better off if ...

Unprecedented amounts of digital data are becoming available nowadays, but frequently the data lack some semantic information necessary to effectively organize these resources. For images in particular, textual annotations that represent the semantics ...

Traditional data warehouses integrate new data during lengthy offline periods, with indexes being dropped and rebuilt for efficiency reasons. There is the idea that these and other factors make them unfit for realtime warehousing. We analyze how a set ...

The existing heuristics for top-k join queries, aiming to minimize the scan-depth, rely heavily on scores and correlation of scores. It is known that for uniformly random scores between two relations of length n, scan-depth of √kn is required. Moreover, ...

The paper explores a hybrid page layout (HPL), combining the advantages of NSM and PAX. The design defines a continuum between NSM and PAX supporting both efficient scans minimizing cache faults and efficient insertions and updates. Our evaluation shows ...

Many large-scale read-only databases and data warehouses use bitmap indices in an effort to speed up data analysis. These indices have the dual properties of compressibility and being able to leverage fast bit-wise operations for query processing. ...

Append-/Log-based Storage Managers (LbSM) for database systems represent a good match for the characteristics and behaviour of Flash technology. LbSM alleviate random writes reducing the impact of Flash read/write asymmetry, increasing endurance and ...

The coverage problem is one of the fundamental problems in sensor networks, which reflects the degree of a region being monitored by sensors. In this paper, we make the first attempt to address the k-coverage verification problem regarding a given query ...

The probabilistic relation model has been used for the compact representation of uncertain data in relational databases. In this paper we present the extended probabilistic relation model, a compact representation for uncertain information that admits ...

Given a sequential input connection, we tackle parallel skyline computation of the read data by means of a spatial tree structure for indexing fine-grained feature vectors. For this purpose, multiple local split decision trees are simultaneously filled ...

Cost models have been following the life cycle of databases. In the first generation, they have been used by query optimizers, where the cost-based optimization paradigm has been developed and supported by most of important optimizers. The spectacular ...

DynamicNet, an effective and efficient algorithm for supporting community evolution detection in time-evolving information networks is presented and experimentally evaluated in this paper. DynamicNet introduces a graph-based model-theoretic approach to ...

It is increasingly common to find XML views used to enforce access control as found in many applications and commercial database systems. To overcome the overhead of view materialization and maintenance, XML views are necessarily virtual. With this ...

In this paper, we study the problem of mining for frequent trajectories, which is crucial in many application scenarios, such as vehicle traffic management, hand-off in cellular networks, supply chain management. We approach this problem as that of ...

A key factor of measuring database performance is query response time, which is dominated by I/O time. Database partitioning is among techniques that can help users reduce the I/O time significantly. However, how to efficiently partition tables in a ...

Data integration systems based on Peer-to-Peer environments have been developed to integrate dynamic, autonomous and heterogeneous data sources on the Web. Some of these systems adopt semantic approaches for clustering their data sources, reducing the ...

In recent years, many researchers have been interested in the problem of Skyline query evaluation because this kind of queries allows to filter high volumes of data. Skyline queries return those objects that are the best ones according to multiple user'...

Skyline queries were introduced to formulate multi-criteria searches. Such a query tries to select in a relation the tuples that optimize all the criteria, called dominant tuples. There rarely exists a single dominant tuple, but usually a set of ...

The management of legal domains is gaining great importance in the context of data management. In fact, the geographical distribution of data as implied -- for example -- by cloud-based services requires that the legal restrictions and obligations are ...

Recently, a great deal of interest for Big Data has risen, mainly driven from a widespread number of research problems strongly related to real-life applications and systems, such as representing, modeling, processing, querying and mining massive, ...