M.Garca & F.Saltor: "Discriminated Operations in Interoperable Databases". In [11].  Home/Search   Document Not in Database   Summary   Related Articles   Check

....other abstractions. BLOOM has a whole set of operators for integration, in particular, discriminated operations like discriminated generalization and specialization by attribute useful for overcoming schematic discrepancies [14] and for building federated schemas that support multiple semantics [7]. 4: The semantic enrichment phase Since the local schemas are very poor semantically as a consequence of the limited expressiveness of traditional data models, their semantic level must be upgraded thru a process where knowledge is discovered and made explicit in an enriched representation. ....

.... collection of person associated in proj assignment s aggreg of s aggreg of meet place: char[15] p name: char[8] founded: date end class id name: char[20] end class class children class car id name int dep on employee s aggreg of s aggreg of person [as owner] birth: date plate: char[7] gender: char[3] model: char[8] end class end class 5: The detection phase 5.1: General approach As mentioned in section 1, the detection of interdatabase semantic relationships, that is the most critical task of the integration process, requires the identification of similarities among the ....

M.Garca & F.Saltor: "Discriminated Operations in Interoperable Databases". In [11].

....Federated DB system. One way to handle it is by having one federated schema for each semantic conceptualization ( SL90] i.e. a federated schema for userA and another for userB. An alternative is to allow a single federated schema to support multiple semantics, for example through discriminants ([GS91]) and differentiate the respective semantics at the external schema level, i.e. an external schema for userA, and another for userB. One of the advantages of the second architecture lies in having a smaller number of federated schemas; on the other hand, it requires a CDM supporting multiple ....

....essential characteristics: Eb, Ec, Ed, SRa, SRb. The basic relational model does not satisfy Eb, Ec, Ed and SRa, even if it complies with SRb ( Sa86] the essential part of Ea, and SRc (relations are the only structure) and can easily be extended with discriminated operations to satisfy SRd ([GS91]) All this applies to version 2 of the relational model ( Co90] except that Ed is satisfied. The RM T model of [Co79] is an improvement over them, because it satisfies the essential parts of Eb and Ec, and of SRa; it complies with SRb ( Sa87] however, it now fails to satisfy SRc, because it ....

M. Garcia & F. Saltor; "Discriminated Operations for Interoperable Databases". Proc. 1st Int. Workshop on Interoperability in Multidatabase Systems, Kyoto.

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