Results 1 - 10 of 1,919

Parallel Query Optimization: Exploiting Bushy and Pipeline Parallelism with Genetic Programs

by Michael Stillger , Myra Spiliopoulou, Johann-Christoph Freytag , 1996
"... Parallel query optimization is one of the hardest problems in the databases area. The various cost models reflecting the query execution parameters determine the structure and size of the solutions space. To explore this space, research has turned towards combinatorial optimization techniques, heuri ..."
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, heuristics and genetic algorithms, which have been primarily studied for sequential query processing. In this study, we propose a genetic programming strategy for the optimization of parallel bushy query execution plans. Genetic programming has evolved from genetic algorithms, and is more flexible

Query evaluation techniques for large databases

by Goetz Graefe - ACM COMPUTING SURVEYS , 1993
"... Database management systems will continue to manage large data volumes. Thus, efficient algorithms for accessing and manipulating large sets and sequences will be required to provide acceptable performance. The advent of object-oriented and extensible database systems will not solve this problem. On ..."
Abstract - Cited by 767 (11 self) - Add to MetaCart
-relational database systems, including iterative execution of complex query evaluation plans, the duality of sort- and hash-based set matching algorithms, types of parallel query execution and their implementation, and special operators for emerging database application domains.

Answering Queries Using Views: A Survey

by Alon Y. Halevy , 2000
"... The problem of answering queries using views is to find efficient methods of answering a query using a set of previously defined materialized views over the database, rather than accessing the database relations. The problem has recently received significant attention because of its relevance to a w ..."
Abstract - Cited by 562 (32 self) - Add to MetaCart
wide variety of data management problems. In query optimization, finding a rewriting of a query using a set of materialized views can yield a more efficient query execution plan. To support the separation of the logical and physical views of data, a storage schema can be described using views over

Pig Latin: A Not-So-Foreign Language for Data Processing

by Christopher Olston, Benjamin Reed, Utkarsh Srivastava, Ravi Kumar, Andrew Tomkins
"... There is a growing need for ad-hoc analysis of extremely large data sets, especially at internet companies where innovation critically depends on being able to analyze terabytes of data collected every day. Parallel database products, e.g., Teradata, offer a solution, but are usually prohibitively e ..."
Abstract - Cited by 607 (13 self) - Add to MetaCart
-level, procedural style of map-reduce. The accompanying system, Pig, is fully implemented, and compiles Pig Latin into physical plans that are executed over Hadoop, an open-source, map-reduce implementation. We give a few examples of how engineers at Yahoo! are using Pig to dramatically reduce the time required

Eddies: Continuously Adaptive Query Processing

by Ron Avnur, Joseph M. Hellerstein - In SIGMOD , 2000
"... In large federated and shared-nothing databases, resources can exhibit widely fluctuating characteristics. Assumptions made at the time a query is submitted will rarely hold throughout the duration of query processing. As a result, traditional static query optimization and execution techniques are i ..."
Abstract - Cited by 411 (21 self) - Add to MetaCart
In large federated and shared-nothing databases, resources can exhibit widely fluctuating characteristics. Assumptions made at the time a query is submitted will rarely hold throughout the duration of query processing. As a result, traditional static query optimization and execution techniques

Informed Prefetching and Caching

by R. Hugo Patterson, Garth A. Gibson, Eka Ginting, Daniel Stodolsky, Jim Zelenka - In Proceedings of the Fifteenth ACM Symposium on Operating Systems Principles , 1995
"... The underutilization of disk parallelism and file cache buffers by traditional file systems induces I/O stall time that degrades the performance of modern microprocessor-based systems. In this paper, we present aggressive mechanisms that tailor file system resource management to the needs of I/O-int ..."
Abstract - Cited by 402 (10 self) - Add to MetaCart
performance on a 150 MHz Alpha equipped with 15 disks running a range of applications including text search, 3D scientific visualization, relational database queries, speech recognition, and computational chemistry. Informed prefetching reduces the execution time of the first four of these applications by 20

Dataflow query execution in a parallel main-memory environment

by Annita N. Wilschut - In Proc. of the International Conference on Parallel and Distributed Information Systems (PDIS , 1991
"... Abstract. In this paper, the performance and characteristics of the execution of various join-trees on a parallel DBMS are studied. The results of this study are a step into the direction of the design of a query optimization strategy that is fit for parallel execution of complex queries. Among othe ..."
Abstract - Cited by 210 (5 self) - Add to MetaCart
Abstract. In this paper, the performance and characteristics of the execution of various join-trees on a parallel DBMS are studied. The results of this study are a step into the direction of the design of a query optimization strategy that is fit for parallel execution of complex queries. Among

The state of the art in distributed query processing

by Donald Kossmann - ACM Computing Surveys , 2000
"... Distributed data processing is fast becoming a reality. Businesses want to have it for many reasons, and they often must have it in order to stay competitive. While much of the infrastructure for distributed data processing is already in place (e.g., modern network technology), there are a number of ..."
Abstract - Cited by 320 (3 self) - Add to MetaCart
to exploit intra-query parallelism, techniques to reduce communication costs, and techniques to exploit caching and replication of data. Furthermore, the paper discusses di erent kinds of distributed systems such as client-server, middleware (multi-tier), and heterogeneous database systems and shows how

Query Optimization for Parallel Execution

by Sumit Ganguly, Tvaqar Hasan, Ravi Krishnamurthy , 1992
"... The decreasing cost of computing makes it economically viable to reduce the response time of decision support queries by using parallel execution to exploit inexpen-sive resources. This goal poses the following query op-timization problem: Mzntmzze response ttme subject to constraints on throughput, ..."
Abstract - Cited by 134 (8 self) - Add to MetaCart
The decreasing cost of computing makes it economically viable to reduce the response time of decision support queries by using parallel execution to exploit inexpen-sive resources. This goal poses the following query op-timization problem: Mzntmzze response ttme subject to constraints on throughput

An Adaptive Query Execution System for Data Integration

by Zachary Ives, Daniela Florescu, Inria Roquencourt, Marc Friedman, Alon Levy, Daniel Weld , 1999
"... Query processing in data integration occurs over networkbound, autonomous data sources. This requires extensions to traditional optimization and execution techniques for three reasons: there is an absence of quality statistics about the data, data transfer rates are unpredictable and bursty, and slo ..."
Abstract - Cited by 226 (21 self) - Add to MetaCart
Query processing in data integration occurs over networkbound, autonomous data sources. This requires extensions to traditional optimization and execution techniques for three reasons: there is an absence of quality statistics about the data, data transfer rates are unpredictable and bursty
Results 1 - 10 of 1,919