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In this paper, we propose a novel, effective and efficient probabilistic pruning criterion for probabilistic similarity queries on uncertain data. Our approach supports a general uncertainty model using continuous probabilistic density functions to describe the (possibly correlated) uncertain attributes of objects. In a nutshell, the problem to be solved is to compute the PDF of the random variable...
We propose a “logic + SQL” framework for set preferences. Candidate best sets are represented using profiles consisting of scalar features. This reduces set preferences to tuple preferences over set profiles. We propose two optimization techniques: superpreference and M-relation. Superpreference targets dominated profiles. It reduces the input size by filtering out tuples not belonging to any best...
The Infobright database engine stores data in column wise chunks in a highly compressed form. Access to data is slowed down by the necessity of fetching required chunks from disk and decompressing them. A prefetching mechanism is meant to perform these tasks shortly before a running query needs the data for processing. The prefetching implementation in Infobright is described and evaluated. An average...
Synchronous execution of queries or Web service requests forces the calling application to block until the query/request is satisfied. The performance of applications can be significantly improved by asynchronous submission of queries, which allows the application to perform other processing instead of blocking while the query is executed, and to concurrently issue multiple queries. Concurrent submission...
SQL is a classical and powerful tool for querying relational databases. However, it is rather hard for inexperienced users to pose SQL queries, as they are required to be proficient in SQL syntax and have a thorough understanding of the underlying schema. To give users gratification, we propose SQLSUGG, an effective and user-friendly keyword-based method to help various users formulate SQL queries...
An important facility to aid keyword search on XML data is suggesting alternative queries when user queries contain typographical errors. Query suggestion thus can improve users' search experience by avoiding returning empty result or results of poor qualities. In this paper, we study the problem of effectively and efficiently providing quality query suggestions for keyword queries on an XML document...
In the context of medical document retrieval, users often under-specified queries lead to undesired search results that suffer from not containing the information they seek, inadequate domain knowledge matches and unreliable sources. To overcome the limitations of under-specified queries, we utilize tags to enhance information retrieval capabilities by expanding users' original queries with context-relevant...
The Arabic web content is growing rapidly and the need for its efficient management is gaining importance and the morphological complexity of Arabic raises many challenges in this regard. This paper reports on some of our work aimed at designing text mining and query pre-processing tools that are able to efficiently process and search large quantities of Arabic web data. In our research we try to...
This paper deals with the negation operator in the context of a bipolar fuzzy relational algebra which makes it possible to handle bipolar fuzzy queries (involving flexible constraints and wishes) and relations. Several possible definitions of the negation are studied and assessed with respect to some desirable properties. A negation operator which complies with all those desirable properties is proposed,...
With the development of virtualization technology, on-demand computing becomes more reliable and acceptable in industry, such as utility computing and IaaS (Infrastructure-as-a-Service) of cloud computing. In virtualized environments, applications are running on VMs (virtual machines) configured with physical computing resources (CPU, memory, etc.). Inevitably, issues about performance management...
Decision optimization is used in many applications such as those for finding the best course of action in emergencies. However, optimization solutions require considerable mathematical expertise and effort to generate effective models. On the other hand, reporting applications over databases are more intuitive and have long been established using the mature database query technology. A decision optimization...
The web size is increasing continuously. Chinese researchers have shown that web growth obeys the Moor's law and the Internet will double in size every 5.32 years. The more the Internet is growing; the more tendencies the people have to use the search engines. Moreover, since most of the commercial search engines are based on keyword indexing, there are many records in their result lists that are...
Emergence of the mobile computing paradigm helps people to work in a much more convenient and efficient way, anywhere and anytime. Today its application areas such as traffic reports, weather forecast, bill paying and healthcare are so popular. The field of data management is also extended with such new services and applications. A mobile database system is a special heterogonous distributed system...
Frequent items detection is one of the valuable techniques in many applications, such as network monitor, network intrusion detection, worm virus detection, and so on. This technique has been well studied on deterministic databases. However, it is a new task on emerging uncertain database. In this paper, a new definition of frequent items detection on uncertain data is defined. Based on it, two efficient...
Understanding the interaction patterns among a set of biological entities in a pathway is an important exercise because it potentially could reveal the role of the entities in biological systems. Although a considerable amount of effort has been directed to the detection and mining of patterns in biological pathways in contemporary research, querying biological pathways remained relatively unexplored...
MS/MS experiments generate hundreds to tens of thousands of fragment ion spectra during the experiment. In the peptide identification, MS/MS spectra are often identified by database searching algorithms such as SEQUEST and Mascot. Most database searching algorithms calculate score functions to compare the experimental MS/MS spectra with theoretical MS/MS spectra of certain peptides derived from protein...
Consistent query answering (CQA) in relational databases under cardinality-based semantics is a well-known approach to dealing with inconsistency between databases and certain integrity constraints (ICs). It computes from a given database all consistent answers to a query that are satisfied by all the C-repairs, where a C-repair is a database that satisfies all the given ICs and minimizes the cardinality...
We propose a possibility theory-based approach to the treatment of missing user preferences in skyline queries. To compensate this lack of knowledge, we show how a set of plausible preferences suitable for the current context can be derived either in a case-based reasoning manner, or using an extended possibilistic logic setting. Uncertain dominance relationships are defined in a possibilistic way...
Record matching is an essential step in duplicate detection as it identifies records representing same real-world entity. Supervised record matching methods require users to provide training data and therefore cannot be applied for web databases where query results are generated on-the-fly. To overcome the problem, a new record matching method named Unsupervised Duplicate Elimination (UDE) is proposed...
Query by humming (QBH) is a method of searching for a songs in a multimedia database system that contains the melody descriptions of songs. The database of songs can be searched by hummed queries. The user hums a melody into a microphone that is connected to any handheld device and the QBH system searches the database of songs which are similar to the input query and returns the result to the user...
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