Approximate Integrity Constraints in Incomplete Databases With Limited Domains

Fuente: arXiv
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Main Authors: Al-atar, Munqath, Sali, Attila
Format: Preprint
Published: 2024
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author Al-atar, Munqath
Sali, Attila
author_facet Al-atar, Munqath
Sali, Attila
contents In case of incomplete database tables, a possible world is obtained by replacing any missing value by a value from the corresponding attribute's domain that can be infinite. A possible key or possible functional dependency constraint is satisfied by an incomplete table if we can obtain a possible world that satisfies the given key or functional dependency. On the other hand, a certain key or certain functional dependency holds if all possible worlds satisfy the constraint, A strongly possible constraint is an intermediate concept between possible and certain constraints, based on the strongly possible world approach (a strongly possible world is obtained by replacing \nul's by a value from the ones appearing in the corresponding attribute of the table). A strongly possible key or functional dependency holds in an incomplete table if there exists a strongly possible world that satisfies the given constraint. In the present paper, we introduce strongly possible versions of multivalued dependencies and cross joins, and we analyse the complexity of checking the validity of a given strongly possible cross joins. We also study approximation measures of strongly possible keys (spKeys), functional dependencies (spFDs), multivalued dependencies (spMVDs) and cross joins (spCJs). We also treat complexity questions of determination of the approximation values.
format Preprint
id arxiv_https___arxiv_org_abs_2402_05057
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Approximate Integrity Constraints in Incomplete Databases With Limited Domains
Al-atar, Munqath
Sali, Attila
Databases
68P15, 68Q15
H.2.1; F.2.2
In case of incomplete database tables, a possible world is obtained by replacing any missing value by a value from the corresponding attribute's domain that can be infinite. A possible key or possible functional dependency constraint is satisfied by an incomplete table if we can obtain a possible world that satisfies the given key or functional dependency. On the other hand, a certain key or certain functional dependency holds if all possible worlds satisfy the constraint, A strongly possible constraint is an intermediate concept between possible and certain constraints, based on the strongly possible world approach (a strongly possible world is obtained by replacing \nul's by a value from the ones appearing in the corresponding attribute of the table). A strongly possible key or functional dependency holds in an incomplete table if there exists a strongly possible world that satisfies the given constraint. In the present paper, we introduce strongly possible versions of multivalued dependencies and cross joins, and we analyse the complexity of checking the validity of a given strongly possible cross joins. We also study approximation measures of strongly possible keys (spKeys), functional dependencies (spFDs), multivalued dependencies (spMVDs) and cross joins (spCJs). We also treat complexity questions of determination of the approximation values.
title Approximate Integrity Constraints in Incomplete Databases With Limited Domains
topic Databases
68P15, 68Q15
H.2.1; F.2.2
url https://arxiv.org/abs/2402.05057