Many scientific experiments produce an enormous amount of data that needs to be explored. Scientific workflows and tools for managing workflows have been designed to streamline the computational processes that manipulate this data, from acquisition to analysis. However, the fact that each system has its own workflow format has greatly hampered efficient sharing and re-use. To address this problem, we propose a general model for workflows, based on OPM, which combines features from popular scientific workflow systems. We use this model to build infrastructure that supports system-agnostic workflow repositories. We describe the implementation of the infrastructure and present an experimental evaluation of its performance. We show that the proposed model and its implementation provide efficient support for queries over large repositories.

Modern relational database management systems provide hybrid XML storage, combining relational and native technologies. Hybrid storage offers many design alternatives for XML data and in this paper we explore how to aid the user in effective design of hybrid storage. In particular we investigate how the XML schema and statistical information about the data can support the storage design process. We present an extended version of our tool HShreX that uses statistical information about a data to enable fast evaluation of alternative hybrid design solutions. In addition we show the benefit of the approach by a first evaluation where we discuss how the tool aids in the storage design and evaluation process.

Modern relational database management systems provide hybrid XML storage, combining relational and native technologies. Hybrid storage offers many design alternatives for XML data. In this paper we explore how to aid the user in effective design of hybrid storage. In particular we investigate how the XML schema and statistical information about the data can support the storage design process. In our previous work, we presented our tool HShreX that uses statistical information about a data set to enable fast evaluation of alternative hybrid design solutions. In this paper, we extend this work by presenting more details about the tool and results of an extended evaluation. In particular, this paper gives a detailed presentation on how the tool aids in the storage design and evaluation process.

Scientific exploration has become a data-intensive process, and increasing amounts of data need to be stored, analyzed, and shared. XML can help address these needs. As concrete examples from systems biology show, native XML storage can be combined with traditional relational databases to offer an effective, usable solution for storing scientific data.

In the field of bioinformatics, there exists a large number of web service providers and many competing standards regarding how data should be represented and interfaced. However, these web services are often hard to use for a non-programmer and it can be especially hard to understand how different services can be used together to create scientific workflows. In this paper we have performed a literature study to identify problems involved in developing interoperable webservices for the bioinformatics community and steps taken by other projects to address them. We have also conducted a case study by developing our own bioinformatic web service to further investigate these problems. Based on our case study we have identified a number of design issues important to consider when designing web services. The paper is concluded by discussing current approaches aimed at making web services easier to use and by presenting our own proposal of an easy-to-use solution for integrating information from web services.

This book constitutes the workshop proceedings of the 14th International Conference on Database Systems for Advanced Applications, DASFAA 2009, held in Brisbane, Australia, in April 2009. The volume contains six workshops, each focusing on specific research issues that contribute to the main themes of the DASFAA conference: The First International Workshop on Benchmarking of XML and Semantic Web Applications (BenchmarkX'09); The Second International Workshop on Managing Data Quality in Collaborative Information Systems (MCIS'09); The 1st International Workshop on Data and Process Provenance (WDPP'09); The First International Workshop on Privacy-Preserving Data Analysis (PPDA'09); The First International Workshop on Mobile Business Collaboration (MBC'09); and the First Ph.D. Workshop.

In the field of bioinformatics, there exists a large number of web service providers and many competing standards regarding how data should be represented and interfaced. However, these web services are often hard to use for a non-expert programmer and it can be especially hard to see how different services can be used together to create scientific workflows. In this paper we have performed a literature study to identify problems involved in developing interoperable web services for the bioinformatics community and steps taken by other projects to, at least in part, address them. We have also conducted a case study by developing our own bioinformatic web service to further investigate these problems.

Workflows are increasingly being used to specify computational tasks, from simulations and data analysis to the creation of Web mashups. Recently, a number of public workflow repositories have become available, for example, myExperiment for scientific workflows, and Yahoo! Pipes. Workflow collections are also commonplace in many scientific projects. Having such collections opens up new opportunities for knowledge sharing and re-use. But for this to become a reality, mechanisms are needed that help users explore these collections and locate useful workflows. Although there has been work on querying workflows, not much attention has been given to presenting query results. In this paper, we take a first look at the requirements for workflow snippets and study alternative techniques for deriving concise, yet informative snippets.