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An architecture for query optimization
Proceedings of the 1982 ACM SIGMOD international conference on Management of data - SIGMOD '82, 1982We describe an optimizer for relational queries to databases stored as flat files and Codasyl networks. We include sophisticated manipulations on a broad range of direct access structures (DAS's). To achieve this with minimum additional code, we allow operations like sort, scan, and join to apply to DAS's, and categorize indexes and other DAS's in ...
David Reiner, Arnon Rosenthal
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Query optimization mechanisms in the cloud environments: A systematic study
International Journal of Communication Systems, 2019The goal of a query optimizer is to provide an optimal Query Execution Plan (QEP) by comparing alternative query plans. In a distributed database system over cloud environment, the relations required by a query plan may be stored at multiple sites.
E. Azhir +4 more
semanticscholar +1 more source
Deterministic and non‐deterministic query optimization techniques in the cloud computing
Concurrency and Computation, 2019Query optimization is considered as one of the main challenges of query processing phases in the cloud environments. The query optimizer attempts to provide the most optimal execution plan by considering the possible query plans. Therefore, the execution
E. Azhir +4 more
semanticscholar +1 more source
2009
Complex queries are becoming commonplace with the growing use of decision support systems. These complex queries often have a lot of common sub-expressions, either within a single query, or across multiple such queries. The focus of this work is to speed up query execution by exploiting these common subexpressions.
Sundararajarao Sudarshan, Prasan Roy
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Complex queries are becoming commonplace with the growing use of decision support systems. These complex queries often have a lot of common sub-expressions, either within a single query, or across multiple such queries. The focus of this work is to speed up query execution by exploiting these common subexpressions.
Sundararajarao Sudarshan, Prasan Roy
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ACM SIGMOD Record, 1996
The strength of commercial query optimizers like DB2 comes from their ability to select an optimal order by generating all equivalent reorderings of binary operators. However, there are no known methods to generate all equivalent reorderings for a SQL query containing joins, outer joins, and groupby aggregations.
Bala Iyer, Piyush Goel
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The strength of commercial query optimizers like DB2 comes from their ability to select an optimal order by generating all equivalent reorderings of binary operators. However, there are no known methods to generate all equivalent reorderings for a SQL query containing joins, outer joins, and groupby aggregations.
Bala Iyer, Piyush Goel
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Multi-Query Optimization for Subgraph Isomorphism Search
Proceedings of the VLDB Endowment, 2016Existing work on subgraph isomorphism search mainly focuses on a-query-at-a-time approaches: optimizing and answering each query separately. When multiple queries arrive at the same time, sequential processing is not always the most efficient.
Xuguang Ren, Junhu Wang
semanticscholar +1 more source
QueryFormer: A Tree Transformer Model for Query Plan Representation
Proceedings of the VLDB Endowment, 2022Machine learning has become a prominent method in many database optimization problems such as cost estimation, index selection and query optimization. Translating query execution plans into their vectorized representations is non-trivial.
Yue Zhao
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Query scheduling in multi query optimization
Proceedings 2001 International Database Engineering and Applications Symposium, 2002Complex queries are becoming commonplace, with the growing use of decision support systems. Decision support queries often have a lot of common sub-expressions within each query, and queries are often run as a batch. Multi query optimization aims at exploiting common sub-expressions, to reduce the evaluation cost of queries, by computing them once and ...
Sundar Vishwanathan +2 more
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2020
When you submit a query to MySQL for execution, it is not as simple as just reading the data and returning it. True, for simple queries requesting all data from a single table, there are not many options how to retrieve the data. However, most queries are more complex – some much more complex – and executing the query exactly as it is written is by no ...
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When you submit a query to MySQL for execution, it is not as simple as just reading the data and returning it. True, for simple queries requesting all data from a single table, there are not many options how to retrieve the data. However, most queries are more complex – some much more complex – and executing the query exactly as it is written is by no ...
openaire +2 more sources
Optimizing query rewriting for multiple queries
Proceedings of the Ninth International Workshop on Information Integration on the Web, 2012We present an scalable algorithm for answering multiple conjunctive queries using views. This is an important problem in query optimization, data integration and ontology-based data access. Since rewriting one conjunctive query using views is an NP-hard problem, we develop an approach where answering n queries takes less than n times the cost of ...
George Konstantinidis, José Luis Ambite
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