Eliminating costly redundant computations from SQL trigger executions
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| Název: | Eliminating costly redundant computations from SQL trigger executions |
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| Autoři: | Llirbat, François, Fabret, Françoise, Simon, Eric |
| Zdroj: | ACM SIGMOD Record ; volume 26, issue 2, page 428-439 ; ISSN 0163-5808 |
| Informace o vydavateli: | Association for Computing Machinery (ACM) |
| Rok vydání: | 1997 |
| Popis: | Active database systems are now in widespread use. The use of triggers in these systems, however, is difficult because of the complex interaction between triggers, transactions, and application programs. Repeated calculations of rules may incur costly redundant computations in rule conditions and actions. In this paper, we focus on active relational database systems supporting SQL triggers. In this context, we provide a powerful and complete solution to eliminate redundant computations of SQL triggers when they are costly. We define a model to describe programs, rules and their interactions. We provide algorithms to extract invariant subqueries from trigger's condition and action. We define heuristics to memorize the most “profitable” invariants. Finally, we develop a rewriting technique that enables to generate and execute the optimized code of SQL triggers. |
| Druh dokumentu: | article in journal/newspaper |
| Jazyk: | English |
| DOI: | 10.1145/253262.253357 |
| Dostupnost: | https://doi.org/10.1145/253262.253357 https://dl.acm.org/doi/10.1145/253262.253357 https://dl.acm.org/doi/pdf/10.1145/253262.253357 |
| Rights: | https://www.acm.org/publications/policies/copyright_policy#Background |
| Přístupové číslo: | edsbas.E2EE73C8 |
| Databáze: | BASE |
Nájsť tento článok vo Web of Science | Abstrakt: | Active database systems are now in widespread use. The use of triggers in these systems, however, is difficult because of the complex interaction between triggers, transactions, and application programs. Repeated calculations of rules may incur costly redundant computations in rule conditions and actions. In this paper, we focus on active relational database systems supporting SQL triggers. In this context, we provide a powerful and complete solution to eliminate redundant computations of SQL triggers when they are costly. We define a model to describe programs, rules and their interactions. We provide algorithms to extract invariant subqueries from trigger's condition and action. We define heuristics to memorize the most “profitable” invariants. Finally, we develop a rewriting technique that enables to generate and execute the optimized code of SQL triggers. |
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| DOI: | 10.1145/253262.253357 |