Normal form relation schemes a new characterization /
A new characterization of relational database schemes in normal forms is given. This characterization is based on the properties of the semilattice of closed sets of attributes. For the problems testing third and Boyce-Codd normal forma, which are known to be ^//'-complete for relation schemes,...
Elmentve itt :
| Szerzők: | |
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| Dokumentumtípus: | Cikk |
| Megjelent: |
1992
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| Sorozat: | Acta cybernetica
10 No. 3 |
| Kulcsszavak: | Számítástechnika, Kibernetika |
| Tárgyszavak: | |
| Online Access: | http://acta.bibl.u-szeged.hu/12502 |
| LEADER | 01411nab a2200253 i 4500 | ||
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| 001 | acta12502 | ||
| 005 | 20220613091941.0 | ||
| 008 | 161015s1992 hu o 0|| eng d | ||
| 022 | |a 0324-721X | ||
| 040 | |a SZTE Egyetemi Kiadványok Repozitórium |b hun | ||
| 041 | |a eng | ||
| 100 | 1 | |a Demetrovics János | |
| 245 | 1 | 0 | |a Normal form relation schemes |h [elektronikus dokumentum] : |b a new characterization / |c Demetrovics János |
| 260 | |c 1992 | ||
| 300 | |a 141-153 | ||
| 490 | 0 | |a Acta cybernetica |v 10 No. 3 | |
| 520 | 3 | |a A new characterization of relational database schemes in normal forms is given. This characterization is based on the properties of the semilattice of closed sets of attributes. For the problems testing third and Boyce-Codd normal forma, which are known to be ^//'-complete for relation schemes, this new characterization helps establish polynomial algorithms if the input is a relation (matrix) rather than a relation scheme. The problem of approximation of an arbitrary family of functional dependencies by one in a normal form is also addressed. | |
| 650 | 4 | |a Természettudományok | |
| 650 | 4 | |a Számítás- és információtudomány | |
| 695 | |a Számítástechnika, Kibernetika | ||
| 700 | 0 | 1 | |a Hencsey Gusztáv |e aut |
| 700 | 0 | 1 | |a Libkin Leonid O. |e aut |
| 700 | 0 | 1 | |a Muchnik Ilya |e aut |
| 856 | 4 | 0 | |u http://acta.bibl.u-szeged.hu/12502/1/cybernetica_010_numb_003_141-153.pdf |z Dokumentum-elérés |