This book constitutes the refereed proceedings of the 17th International Conference on Model Driven Engineering Languages and Systems, MODELS 2014, held in Valencia, Spain, in September/October 2014. The 41 full papers presented in this volume were carefully reviewed and selected from a total of 126 submissions. The scope of the conference series is broad, encompassing modeling languages, methods, tools, and applications considered from theoretical and practical angles and in academic and industrial settings. The papers report on the use of modeling in a wide range of cloud, mobile, and web computing, model transformation behavioral modeling, MDE: past, present, future, formal semantics, specification, and verification, models at runtime, feature and variability modeling, composition and adaptation, practices and experience, modeling for analysis, pragmatics, model extraction, manipulation and persistence, querying, and reasoning.

This book constitutes the refereed proceedings of the 6th International Conference on Extending Database Technology, EDBT '98, held in Valencia, Spain, in March 1998. The 32 revised full papers presented together with one invited keynote were selected from a total of 191 submissions. The book is divided in sections on similarity search and indexing, query optimization on the Web, Algorithms for data mining, modelling in OLAP, query processing and storage management, aggregation and summary data, object-oriented and active databases, view maintenance and integrity, databases and the Web, workflow and scientific databases.

The Database and Expert Systems Application -DEXA - conferences are mainly oriented to establish a state-of-the art forum on Database and Expert System applications. But Practice without Theory has no sense, as Leonardo said five centuries ago. In this Conference we try a comprornise between these two complementary aspects. A total of 5 sessions are application-oriented, ranging from classical applications to more unusual ones in Software Engineering. Recent research aspects in Databases, such as activity, deductivity and/or Object Orientation are also present in DEXA 92, as weIl as the implication of the new "data models" such as OO-Model, Deductive Model, etc .. included in the Modelling sessions. Other areas of interest, such as Hyper-Text and Multimedia application, together with the classical field of Information Retrieval are also considered. FinaIly, Implementation Apects are reflected in very concrete fields. A total of of nearly 200 papers submitted from all over the world were sent to DEXA 92. Only 90 could be accepted. A Poster session has also been establishcd. DEXA 90 was held in Vienna, Austria; DEXA 91 in Berlin, Germany; and DEXA 92 will take place in Valencia, Spain, where we are celebrating the discovery of thc New World just five centurics ago, in Leonardo's age. Both the quality of the Conference and the compromise between Practice and Thcory are duc to the credit of all the DEXA 92 authors.