This paper addresses the question of updating relational databases through XML views. Using query trees to capture the notions of selection, projection, nesting, grouping, and heterogeneous sets found throughout most XML query languages, we show how XML views expressed using query trees can be mapped to a set of corresponding relational views. We then show how updates on the XML view are mapped to updates on the corresponding relational views. Existing work on updating relational views can then be leveraged to determine whether or not the relational views are updatable with respect to the relational updates, and if so, to translate the updates to the underlying relational database.

XML has become an important medium for data exchange, and is frequently used as an interface to -- i.e. a view of -- a relational database. Although much attention has been paid to the problem of querying relational databases through XML views, the problem of updating relational databases through XML views has not been addressed. In this paper we investigate how a subset of XQuery can be used to build updatable XML views, so that an update to the view can be unambiguously translated to a set of updates on the underlying relational database, assuming that certain key and foreign key constraints hold. In particular, we show how views defined in this subset of XQuery can be mapped to a set of relational views, thus transforming the problem of updating relational databases through XML views into a classical problem of updating relational databases through relational views.

This paper addresses the question of updating relational databases through XML views. Using a notion of query trees to capture the notions of selection, projection, nesting, grouping, and heterogeneous sets found throughout most XML query languages, we show how XML views expressed using query trees can be mapped to a set of corresponding relational views. We then show how updates on the XML view are mapped to updates on the corresponding relational views. Existing work on updating relational views can then be leveraged to determine whether or not the relational views are updatable with respect to the relational updates, and if so, to translate the updates to the underlying relational database.

Workload information has proved to be a crucial component for database-administration tasks as well as for analysis of query logs to understand user behavior and system usage. These tasks require the ability to summarize large SQL workloads. In this paper, we identify primitives that are important to enable many important workload-summarization tasks. These primitives also appear to be useful in a variety of practical scenarios besides workload summarization. Today’s SQL is inadequate to express these primitives conveniently. We discuss possible extensions to SQL and the relational engine to efficiently support such summarization primitives. 1.

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The paper presents a framework for publishing relational databases in textual documents such as mails, HTML pages, L ATEX or BibTex files, plain texts, etc. The publication process relies on a mapping of the relational database to a virtual data graph which supports navigation operators. Applications can express the data they need by navigating in the graph. The result is then obtained by producing, during the navigation, textual fragments whose concatenation constitutes the final document. These operations are provided by a declarative query language over virtual graphs, named DOCQL. The actual evaluation of a DOCQL query is done by executing interrelated SQL queries over the relational database. By considering these queries as a whole, a global optimization process takes place during the translation. DOCQL aims at reaching a good tradeoff: allowing a simple, direct and very concise specification of database publishing applications whose semantics depends only on the database instance, while keeping an efficient evaluation. We illustrate its features with the conference management system MYREVIEW. 1

XML has been explored by both research and industry communities. More than 5500 papers were published on different aspects of XML. With so many publications, it is hard for someone to decide where to start. Hence, this paper presents some of the research topics on XML, namely: XML on relational databases, query processing, views, data matching, and schema evolution. It then summarizes some (some!) of the most relevant or traditional papers on those subjects. 1.