Data Mining Systems -- Mining and Explaining Relationships in Wikipedia -- Publishing Time-Series Data under Preservation of Privacy and Distance Orders -- Efficient Discovery of Generalized Sentinel Rules -- Parallelism and Query Planning -- Compound Treatment of Chained Declustered Replicas Using a Parallel Btree for High Scalability and Availability -- Query Reuse Based Query Planning for Searches over the Deep Web -- Efficient Parallel Data Retrieval Protocols with MIMO Antennae for Data Broadcast in 4G Wireless Communications -- Data Warehousing and Decision Support Systems -- Inferring Aggregation Hierarchies for Integration of Data Marts -- Schema Design Alternatives for Multi-granular Data Warehousing -- An Agent Model of Business Relationships -- Temporal, Spatial and High Dimensional Databases (Short Papers) -- Pivot Selection Method for Optimizing both Pruning and Balancing in Metric Space Indexes -- Minimum Spanning Tree on Spatio-Temporal Networks -- Data Warehousing and Data Mining Algorithms (Short Papers) -- Real-Time Temporal Data Warehouse Cubing -- PAGER: Parameterless, Accurate, Generic, Efficient kNN-Based Regression -- B2R: An Algorithm for Converting Bayesian Networks to Sets of Rules -- Automatic Morphological Categorisation of Carbon Black Nano-aggregates -- Data Mining Algorithms (I) -- Towards Efficient Mining of Periodic-Frequent Patterns in Transactional Databases -- Lag Patterns in Time Series Databases -- An Efficient Computation of Frequent Queries in a Star Schema -- Information Retrieval and Database Systems (Short Papers) -- Evaluating Evidences for Keyword Query Disambiguation in Entity Centric Database Search -- Typicality Ranking of Images Using the Aspect Model -- Plus One or Minus One: A Method to Browse from an Object to Another Object by Adding or Deleting an Element -- Using Transactional Data from ERP Systems for Expert Finding -- A Retrieval Method for Earth Science Data Based on Integrated Use of Wikipedia and Domain Ontology -- Query Processing and Optimization -- Consistent Answers to Boolean Aggregate Queries under Aggregate Constraints -- Identifying Interesting Instances for Probabilistic Skylines -- GPU-WAH: Applying GPUs to Compressing Bitmap Indexes with Word Aligned Hybrid -- Containment of Conjunctive Queries with Negation: Algorithms and Experiments -- Application of DB Systems, Similarity Search and XML -- Ranking Objects Based on Attribute Value Correlation -- Efficiently Finding Similar Objects on Ontologies Using Earth Mover's Distance -- Towards a "More Declarative" XML Query Language -- Reducing Graph Matching to Tree Matching for XML Queries with ID References -- Data Mining Algorithms (II) -- Improving Alternative Text Clustering Quality in the Avoiding Bias Task with Spectral and Flat Partition Algorithms -- An Efficient Similarity Join Algorithm with Cosine Similarity Predicate -- An Efficient Algorithm for Reverse Furthest Neighbors Query with Metric Index -- Pervasive Data and Sensor Data Management (Short Papers) -- A Scalable and Self-adapting Notification Framework -- Enrichment of Raw Sensor Data to Enable High-Level Queries -- Data Mining Algorithms (III) -- Transductive Learning from Textual Data with Relevant Example Selection -- A Discretization Algorithm for Uncertain Data.

st We welcome you to the proceedings of the 21 International Conference on Database and Expert Systems Applications held in Bilbao. With information and database s- tems being a central topic of computer science, it was to be expected that the integ- tion of knowledge, information and data is today contributing to the again rapidly increasing attractiveness of this field for researchers and practitioners. Since its foundation in 1990, DEXA has been an annual international conference, located in Europe, which showcases state-of-the-art research activities in these areas. DEXA 2010 continued this tradition and provided a forum for presenting and discu- ing research results in the area of database and intelligent systems and advanced - search topics, applications and practically relevant issues related to these areas. It offered attendees the opportunity to extensively discuss requirements, problems, and solutions in the field in the pleasant atmosphere of the city of Bilbao, which is known for its driving industriousness, its top cultural venues and its rich and inspiring he- tage and lifestyle. The University of Deusto with its great educational and research traditions, and the hospitality which the university and the city are so famous for, set the stage for this year's DEXA conference. This volume contains the papers selected for presentation at the DEXA conference.