Results 291 to 300 of about 2,100,534 (347)
Some of the next articles are maybe not open access.
C-store: a column-oriented DBMS
2018This paper presents the design of a read-optimized relational DBMS that contrasts sharply with most current systems, which are write-optimized. Among the many differences in its design are: storage of data by column rather than by row, careful coding and packing of objects into storage including main memory during query processing, storing an ...
Mike Stonebraker +13 more
openaire +1 more source
Preferential orientation of spheroidal particles in wavy flow
Journal of Fluid Mechanics, 2018We report a theoretical study of the angular dynamics of small, non-inertial spheroidal particles in a linear wave field. We recover the observation recently reported by DiBenedetto et al. (J. Fluid Mech., vol. 837, 2018, pp.
Michelle H. DiBenedetto, N. Ouellette
semanticscholar +1 more source
Column-Oriented Data Store for Astrophysical Data
2014 25th International Workshop on Database and Expert Systems Applications, 2014Astrophysical databases have used proprietary formats (especially the FITS format) to represent measured data and related metadata. The design of the FITS format was influenced by punch cards, thus it is extremely inappropriate for modern hardware. Even though this format is well established in the domain of astrophysics and will be definitely used as ...
Jakub Yaghob +3 more
openaire +1 more source
Business Intelligence and Column-Oriented Databases
2014In recent years, NoSQL databases are becoming more and more popular. We distinguish several different types of such databases and column-oriented databases are very important in this context, for sure. The purpose of this paper is to see how column-oriented databases can be used for data warehousing purposes and what the benefits of such an approach ...
Rabuzin, Kornelije, Modrušan, Nikola
openaire +2 more sources
Column-oriented Database Systems and XML Compression
Proceedings of 3rd International Conference on Data Management Technologies and Applications, 2014With the renewed industrial and academic interest in Column-Oriented Database Management Systems, a lot of interest has been shown in the area of software optimizations designed to improve the efficiency of queries in the Column-Oriented domain. Meanwhile, XML database management systems are often considered in the context of mapping its hierarchal ...
Jan Krzysztof Miziołek +2 more
openaire +1 more source
Column-oriented query processing for row stores
Proceedings of the ACM 14th international workshop on Data Warehousing and OLAP, 2011Column-oriented DBMSs have gained increasing interest due to their superior performance for analytical workloads. Prior efforts tried to determine the possibility of simulating the query processing techniques of column-oriented systems in row-oriented databases, in a hope to improve their performance, especially for OLAP and data warehousing ...
Amr El-Helw +4 more
openaire +1 more source
A model for the formation of orientation columns
Proceedings of the Royal Society of London. Series B. Biological Sciences, 1982A mathematical model is proposed to describe the formation of orientation columns in mammalian visual cortex. The model is similar in concept to that proposed for ocular dominance column formation (Swindale 1980), the essential difference being that orientation is a vector rather than a scalar variable.
openaire +2 more sources
High-resolution mapping of iso-orientation columns by fMRI
Nature Neuroscience, 2000Blood-oxygenation level-dependent (BOLD) functional magnetic resonance imaging (fMRI) is an important tool for localizing brain functions in vivo. However, the ability of BOLD fMRI to map cortical columnar structures is highly controversial, as the ultimate functional specificity of BOLD remains unknown.
Kim, DS Kim, Dae-Shik +2 more
openaire +2 more sources
Column-based RLE in row-oriented database
2009 International Conference on Cyber-Enabled Distributed Computing and Knowledge Discovery, 2009In database systems, disk I/O performance is usually the bottleneck of the whole query processing. Among many techniques, compression is one of the most important ones to reduce disk accesses so to improve system performance. RLE (Run-Length Encoding) is one light-weight compression algorithm which incurs negligible CPU cost.
openaire +1 more source
Biomimetic Arrays of Oriented Helical ZnO Nanorods and Columns
Journal of the American Chemical Society, 2002Extended helical or chiral nanostructures are usually associated with biomolecules but are mostly absent in synthetic materials. Here we report the first synthesis of unusual oriented and extended helical nanostructures in synthetic ceramics. Large arrays of oriented helical ZnO nanorods and columns are formed using simple citrate ions to control the ...
Zhengrong R, Tian +4 more
openaire +2 more sources