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290
RankSQL: Query algebra and optimization for relational top-k queries
- In SIGMOD
, 2005
"... This paper introduces RankSQL, a system that provides a systematic and principled framework to support efficient evaluations of ranking (top-k) queries in relational database systems (RDBMS), by extending relational algebra and query optimization. Previously, top-k query processing is studied in the ..."
Abstract
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Cited by 110 (17 self)
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-based method to estimate the cardinality of rank-aware operators, for costing plans. Our experiments show the validity of our framework and the accuracy of the proposed estimation model. 1.
Selectivity Estimation for Extraction Operators over Text Data
- VLDB
, 2010
"... Recently, there has been increasing interest in extending relational query processing to efficiently support extraction operators, such as dictionaries and regular expressions, over text data. Many text processing queries are sophisticated in that they involve multiple extraction and join operators, ..."
Abstract
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Cited by 1 (0 self)
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Recently, there has been increasing interest in extending relational query processing to efficiently support extraction operators, such as dictionaries and regular expressions, over text data. Many text processing queries are sophisticated in that they involve multiple extraction and join operators
Abstract Cost modeling of spatial operators using non-parametric regression q
, 2006
"... In an object-relational database management system, a query optimizer requires users to provide cost models of userdefined functions. The traditional approach is analytical, that is, it builds a cost model generated as a result of analyzing the query processing steps. This analytical approach is dif ..."
Abstract
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estimation. We demonstrate the simplicity and efficacy of this approach through experiments for three spatial operators—the range query, the window query, and the k-nearest neighbor query—commonly used in spatial databases, using both real and synthetic data sets.
Estimation of Query-Result Distribution and its Application in Parallel- Join Load Balancing
"... Many commercial database systems use some form of statistics, typically histograms, to summa-rize the contents of relations and permit efficient estimation of required quantities. While there has been considerable work done on identifying good histograms for the estimation of query-rest&sizes, l ..."
Abstract
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also study the effectiveness of these optimal his-tograms in the context of an important application that requires estimates for the data distribution of a query result: load-balancing for parallel Hybrid hash joins. We derive a cost formula to capture the effect of data skew in both the input and out
Facing Imbalanced Data Recommendations for the Use of Performance Metrics
"... Abstract—Recognizing facial action units (AUs) is important for situation analysis and automated video annotation. Previous work has emphasized face tracking and registration and the choice of features classifiers. Relatively neglected is the effect of imbalanced data for action unit detection. Whil ..."
Abstract
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Cited by 9 (1 self)
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. While the machine learning community has become aware of the problem of skewed data for training classifiers, little attention has been paid to how skew may bias performance metrics. To address this question, we conducted experiments using both simulated classifiers and three major databases that differ
Effect of Data Collection Period Length on Marginal Cost Models for Heavy Equipment
"... Equipment managers can apply either the cumulative cost or period cost based (PCB) methodology to estimate operating costs of heavy equipment, both of which rely on historical data. Cumulative cost methodology requires data to be available over the entire life of the machine, while period cost base ..."
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Equipment managers can apply either the cumulative cost or period cost based (PCB) methodology to estimate operating costs of heavy equipment, both of which rely on historical data. Cumulative cost methodology requires data to be available over the entire life of the machine, while period cost
Disk and Tape Storage Cost Models
"... The current and projected costs of storage are a critical issue as organizations face an explosive growth in data. While the cost of purchasing storage hardware is readily available from vendors, there is little published literature that describes the total cost of providing storage from an operatio ..."
Abstract
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an operational perspective. This paper describes current estimates of both disk and tape storage based on operational experience at the San Diego Supercomputer Center which operates a large-scale storage infrastructure. These costs include not only the storage hardware costs, but also the costs of supporting
Measuring the Non-Pecuniary Costs of Triple Trailer Operation in Oregon: A Contingent Valuation Approach
, 1994
"... The purpose of this study is to measure the costs of the perceived safety threat from triple trailer operation in Oregon. This is done using the political referendum model of a common non-market valuation technique, contingent valuation. Specifically, the average cost of allowing triples will be fou ..."
Abstract
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will be found so that comparison with previously estimated benefits will provide a measure of net social welfare associated with triple trailer use. The data were collected through in-person interviews conducted in five regions in Oregon. Questions relating to the respondents ' attitudes toward triple
Private property and economic efficiency: a study of a common-pool resource
- Journal of Law and Economics
, 2000
"... The British Columbia halibut fishery provides a natural experiment of the effects of “privatizing the commons”. Using firm-level data from the fishery two years before private harvesting rights were introduced, the year they were impl mented and three years afterwards, a stochastic frontier is estim ..."
Abstract
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Cited by 52 (5 self)
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is estimated to test for changes in technical, allocative and economic efficiency. Despite som improvement in short-run measures of cost efficiency, overall the fishing fleet still remains well below the best practice frontier. The relatively few short-run efficiency gains are attributed to deficiencies
Results 1 - 10
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290
