Browsing by Subject "Relational databases"
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Item Assignment of global information system coordinates to classical museum localities for relational database analyses(Texas Tech University, 1999-12) Knyazhnitskiy, OleksiyMany decisions are made based on information concerning the flora and fauna of the world. With the development of a large number of technological breakthroughs, such as computers, DNA sequencers, satellite imagery, and image analyzers, etc. the volume of knowledge available conceming plants and animals is rapidly expanding and has grown beyond our ability to examine each study and data set in the classically employed "hands on" analyses. To more effectively share and interrogate data sets, a new field of science has evolved called bioinformatics. At the heart of bioinformatics is the ability to use computers to examine massive data files in a critical synthesis. These syntheses employ relational databases to examine the geographical and temporal relationships compared to other data sets. The Museum of Texas Tech University has been archiving biological specimens as a source of information on biocomplexity, disease, affects of agriculture, etc. These collections of biological voucher specimens are a valuable source of information that may be explored in a relational format. A new Relational Database Management System was designed to perform operations and increase the purpose of the electronic database (Monk, 1998). The Natural Science Research Lab's (NSRL) current collection was constructed to meet the needs of scientists and biologists, and increase the potential of the collection using the ongoing technological development of computer software and hardware (Baker et al., 1996). A problem to such use is that the data have to be in a format that is compatible with computer analysis. For example, a location such as 10 MI S LUBBOCK cannot be recognized in a geographical context without assistance and extra computer time. Two types of locality data. Universal Transverse Mercator coordinates (UTM) and longitude and latitude, can be easily utilized by computer software. UTM coordinates are numerical data that depict exact geographical locations on a map. A world map is divided into 60 zones. To assign UTM coordinates for a specific location, the position within defined zones is established. For instance, the state of Texas is situated in zones thirteen, fourteen and fifteen (see Figure 1.1). Units express UTM coordinates in meters, so that the accuracy of a geographical location is no more than one meter.Item Evaluation of relational database implementation of triple-stores(2011-05) Funes, Diego Leonardo; Miranker, Daniel P.; Barber, K. SuzanneThe Resource Description Framework (RDF) is the logical data model of the Semantic Web. RDF encodes information as a directed graph using a set of labeled edges known formally as resource-property-value statements or, in common usage, as RDF triples or simply triples. Values recorded in RDF triple form are either Universal Resource Identifiers (URIs) or literals. The use of URIs allows links between distributed data sources, which enables a logical model of data as a graph spanning the Internet. SPARQL is a standard SQL-like query language on RDF triples. This report describes the translation of SPARQL queries to equivalent SQL queries operating on a relational representation of RDF triples, and the physical optimization of that representation using the IBM DB2 relational database management system. Performance was evaluated using the Berlin SPARQL Benchmark. The results show that the implementation can perform well on certain queries, but more work is required to improved overall performance and scalability.Item Integrating relational databases with the Semantic Web(2015-05) Sequeda, Juan Federico; Miranker, Daniel P.; Arenas, Marcelo; Batory, Don; Cannata, Phil; Cook, WilliamAn early vision in Computer Science was to create intelligent systems ca- pable of reasoning on large amounts of data. Independent results in the areas of Description Logic and Relational Databases have advanced us towards this vision. Description Logic research has advanced the understanding of the tradeoff between the computational complexity of reasoning and the expressiveness of logic languages, and now underpins the Semantic Web. The Semantic Web comprises a graph data model (RDF), an ontology language for knowledge representation and reasoning (OWL) and a graph query language (SPARQL). Database research has advanced the theory and practice of management of data, embodying features such as views and recursion which are capable of representing reasoning. Despite the independent advances, the interface between Relational Databases and Semantic Web is poorly understood. This dissertation revisits this vision with respect to current technology and addresses the following question: How and to what extent can Relational Databases be integrated with the Semantic Web? The thesis is that much of the existing Relational Database infrastructure can be reused to support the Semantic Web. Two problems are studied. Can a Relational Database be automatically virtualized as a Semantic Web data source? This paradigm comprises a single Relational Database. The first contribution is an automatic direct mapping from a Relational Database schema and data to RDF and OWL. The second contribution is a method capable of evalu- ating SPARQL queries against the Relational Database, per the direct mapping, by exploiting two existing relational query optimizations. These contributions are embodied in a system called Ultrawrap. Empirical analysis consistently yield that SPARQL query execution performance on Ultrawrap is comparable to that of SQL queries written directly for the relational representation of the data. Such results have not been previously achieved. Can a Relational Database be mapped to existing Semantic Web ontologies and act as a reasoner? This paradigm comprises an OWL ontology including inheritance and transitivity, a Relational Database and mappings between the two. A third contribution is a method for Relational Databases to support inheritance and transitivity by compiling the ontology as mappings, implementing the mappings as SQL views, using SQL recursion and optimizing by materializing a subset of views. This contribution is implemented in an extension of Ultrawrap. Empirical analysis reveals that Relational Databases are able to effectively act as reasoners.Item Relational database applications' optimization and performance study(Texas Tech University, 1998-08) Thiruvaipati, PrashanthThe objective of the thesis is to develop efficient query processing techniques for large relational database applications since, when such applications have to process more than a million records, performance becomes a key issue. Some techniques rely upon massive hardware architectures and new database software to improve efficiency of large database systems. One of the objectives of the thesis, however, is to develop optimization techniques using existing hardware and software. Performance improvement may be achieved by the use of parallel application processes that can process different fragments of a database at the same time. Further performance improvement is achieved by using dynamic SQL and simulating an SQL outer join in the 'C programming language. Simulating the SQL function MAX and proper locking mechanism resulted in marginal performance improvement. Database design to support the use of parallel application processes and the other techniques is presented. Applications are built to test the techniques and the performance results are presented and discussed. Multiple test cases are run for each technique to ensure that the results are similar in time. For each technique, the scenarios of maximum performance improvement, the underlying mechanism, and possible limitations are discussed.Item Relational social media search engine(2016-12)