Traditional optimizers fail to pick good execution plans, when faced with increasingly complex queries and large data sets. This failure is even more acute in the context of XQuery, due to the structured nature of the XML language. To overcome the vulnerabilities of traditional optimizers, we have previously proposed ROX, a Run-time Optimizer for XQueries, which interleaves optimization and execution of full tables. ROX has proved to be robust, even in the presence of strong correlations, but it has one limitation: it uses full materialization of intermediate results making it unsuitable for pipelined systems. Therefore, this paper proposes ROX-sampled, a variant of ROX, which executes small data samples, thus generating smaller intermediat...
One approach to building an efficient XML query processor is to use a relational database system to ...
This paper presents an extensive and detailed experimental evaluation of XQuery processors. The stud...
Abstract. The automated optimization of declarative user queries is a classical hallmark of database...
Traditional optimizers fail to pick good execution plans, when faced with increasingly complex queri...
Query optimization is the most important and complex phase of answering a user query. While sufficie...
Optimization of complex XQueries combining many XPath steps and joins is currently hindered by the a...
We demonstrate ROX, a run-time optimizer of XQueries, that focuses on finding the best execution ord...
We demonstrate ROX, a run-time optimizer of XQueries, that focuses on finding the best execution ord...
Optimization of complex XQueries combining many XPath steps and joins is currently hindered by the a...
Dans cette thèse nous étudions l'optimisation de l'évaluation des requêtes XQuery dans les bases de ...
As more data is stored in XML and more applications need to process this data, XML query optimizatio...
A key assumption underlying query optimization schemes for parallel processing is that their cost mo...
We study XML stream-specific schema-based optimization. We assume a widely-adopted automata-based ...
Computing complex statistics on large amounts of data is no longer a corner case, but a daily challe...
Computing complex statistics on large amounts of data is no longer a corner case, but a daily challe...
One approach to building an efficient XML query processor is to use a relational database system to ...
This paper presents an extensive and detailed experimental evaluation of XQuery processors. The stud...
Abstract. The automated optimization of declarative user queries is a classical hallmark of database...
Traditional optimizers fail to pick good execution plans, when faced with increasingly complex queri...
Query optimization is the most important and complex phase of answering a user query. While sufficie...
Optimization of complex XQueries combining many XPath steps and joins is currently hindered by the a...
We demonstrate ROX, a run-time optimizer of XQueries, that focuses on finding the best execution ord...
We demonstrate ROX, a run-time optimizer of XQueries, that focuses on finding the best execution ord...
Optimization of complex XQueries combining many XPath steps and joins is currently hindered by the a...
Dans cette thèse nous étudions l'optimisation de l'évaluation des requêtes XQuery dans les bases de ...
As more data is stored in XML and more applications need to process this data, XML query optimizatio...
A key assumption underlying query optimization schemes for parallel processing is that their cost mo...
We study XML stream-specific schema-based optimization. We assume a widely-adopted automata-based ...
Computing complex statistics on large amounts of data is no longer a corner case, but a daily challe...
Computing complex statistics on large amounts of data is no longer a corner case, but a daily challe...
One approach to building an efficient XML query processor is to use a relational database system to ...
This paper presents an extensive and detailed experimental evaluation of XQuery processors. The stud...
Abstract. The automated optimization of declarative user queries is a classical hallmark of database...