Search results for "query language"
showing 10 items of 39 documents
SQL Education
2020
Structured Query Language (SQL) skills are crucial in software engineering and computer science. However, teaching SQL effectively requires both pedagogical skill and considerable knowledge of the language. Educators and scholars have proposed numerous considerations for the betterment of SQL education, yet these considerations may be too numerous and scattered among different fora for educators to find and internalize, as no systematic mappings or literature reviews regarding SQL education have been conducted. The two main goals of this mapping study are to provide an overview of educational SQL research topics, research types, and publication fora, and to collect and propagate SQL teachi…
Language-Integrated Privacy-Aware Distributed Queries
2019
Distributed query processing is an effective means for processing large amounts of data. To abstract from the technicalities of distributed systems, algorithms for operator placement automatically distribute sequential data queries over the available processing units. However, current algorithms for operator placement focus on performance and ignore privacy concerns that arise when handling sensitive data. We present a new methodology for privacy-aware operator placement that both prevents leakage of sensitive information and improves performance. Crucially, our approach is based on an information-flow type system for data queries to reason about the sensitivity of query subcomputations. Ou…
Expressive and efficient pattern languages for tree-structured data (extended abstract)
2000
It would be desirable to have a query language for tree-structured data that is (1) as easily usable as SQL, (2) as expressive as monadic second-order logic (MSO), and (3) efficiently evaluable. The paper develops some ideas in this direction. Towards (1) the specification of sets of vertices of a tree by combining conditions on their induced subtree with conditions on their path to the root is proposed. Existing query languages allow regular expressions (hence MSO logic) in path conditions but are limited in expressing subtree conditions. It is shown that such query languages fall short of capturing all MSO queries. On the other hand, allowing a certain guarded fragment of MSO-logic in the…
The Effects of Database Complexity on SQL Query Formulation
2020
In Structured Query Language (SQL) education, students often execute queries against a simple exercise database. Recently, databases that are more realistic have been utilized to the effect that students find exercises more interesting and useful, as these databases more accurately mimic databases students are likely to encounter in their future work environments. However, using even the most engaging database can be counterproductive to learning, if a student is not able to formulate correct queries due to the complexity of the database schema. Scientific evidence on the effects of database complexity on student’s query formulation is limited, and with queries from 744 students against thr…
Integration of Spatial processing and knowledge Processing through the Semantic Web Stack
2011
International audience; This paper presents the integration process of spatial technologies and Semantic Web technologies and its associated tool. The result of this work is a spatial query and rule engine of spatial. To do so, existing ontology with spatial elements is adjusted in order to process the spatial knowledge through spatial technologies. This paper outlines the methods and the processes of these adjustments and how results are returned by our tool. The SWRL and the SPARQL language are extended for spatial purpose and the existing OWL ontology wine is used as an application example.
Knowledge Extraction from Healthcare Data Using User-Adaptable Keywords-Based Query Language
2020
Nowadays, the volume of the information gathered by any organization increases more and more rapidly. It is essential to be able to use this information efficiently for it to benefit the operation of the organization. There is no point of gathering the information if it is not converted into knowledge. The knowledge extraction process becomes the backbone of any successful organization. Moreover, the extraction of the knowledge must be quick and efficient, so that the newly-obtained knowledge can be put in use at once. The problem addressed in this paper is how to allow the domain expert to extract the knowledge from their information systems themselves without involving the third party in …
On Diving in Trees Thomas Schwentick
2000
The paper is concerned with queries on tree-structured data. It defines fragments of first-order logic (FO) and FO extended by regular expressions along paths. These fragments have the same expressive power as the full logics themselves. On the other hand, they can be evaluated reasonably efficient, even if the formula which represents the query is considered as part of the input.
QUEXME: A Query Expansion Method Applied to Water Information System
2009
The aim of the paper is to present and apply a QUery EXpansion MEthod called QUEXME while querying the Euro-Mediterranean Information System (EMWIS) on know-how in the Water sector. EMWIS provides a strategic tool for exchanging information and knowledge in the water sector between and within the Euro Mediterranean partnership countries (www.emwis.net). Information retrieval on the web or through some cooperation of information sources or some general knowledge bases is a complex process and a great challenge with the emergence of the semantic web. The aim of the query expansion method is to help and guide users to build their requests giving them some usually related terms close to their q…
Modeling and Query Language for Hospitals
2013
So far the traditional process modeling languages have found a limited use in the hospital settings. One of the reasons behind this delay has been the lack of clear definition of the sequence of activities that are carried out in the hospital. We propose a new modeling language (as a profile of UML Class diagrams) that captures all the useful features from various UML diagrams and can be used in modeling of the hospitals. Based on the modeling language, we have developed an easy-to-perceive graphical query language, which allows the physicians to retrieve directly from the various hospital databases information they need to better understand the flow of clinical processes.
Towards Graphical Query Notation for Semantic Databases
2015
We describe a notation and a tool for schema-enabled visual/diagrammatic creation of SPARQL queries over RDF databases. The notation and the tool support both the standard basic query pattern comprising a main query class and possibly linked condition classes and means for aggregate query definition and placing conditions over aggregates including also aggregation of aggregate results. We discuss the applicability of the tool for ad-hoc query formulation in practical use cases.