Checking query containment with the CQC method
| Autor: | Ernest Teniente, Carles Farré, Toni Urpí |
|---|---|
| Rok vydání: | 2005 |
| Předmět: |
Soundness
Containment (computer programming) Information Systems and Management Theoretical computer science Computer science Database schema InformationSystems_DATABASEMANAGEMENT Construct (python library) computer.software_genre Constructive Variable (computer science) Data mining Completeness (statistics) computer Counterexample |
| Zdroj: | Data & Knowledge Engineering. 53:163-223 |
| ISSN: | 0169-023X |
| DOI: | 10.1016/j.datak.2004.08.002 |
| Popis: | We present the Constructive Query Containment (CQC) method to check query containment and query containment under constraints for queries over databases with safe negation in both IDB and EDB subgoals and with or without built-in predicates. The aim of the CQC method is to construct a counterexample that proves that the query containment relationship being checked does not hold. The method uses different Variable Instantiation Patterns (VIPs) to generate only relevant counterexamples according to the syntactic properties of the queries and the databases considered in each test.The main contribution of the CQC method is threefold: it handles broader cases of queries and database schemas than most previous methods, it checks "true" containment instead of uniform containment (which is a sufficient but not necessary condition for containment) and it is not less efficient than other methods for the cases that they handle. Moreover, we prove also soundness and completeness of our method both for success and for failure. |
| Databáze: | OpenAIRE |
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