Chang, Y., Raschid, L. and Dorr, B., Transforming queries from a relational schema to an equivalent object schema: a prototype based on F-logic, Proceedings of the International Symposium on Methodologies for Intelligent Systems, 1994.  Home/Search   Document Details and Download   Summary   Related Articles   Check

....mapping problem [2] 12] Database reverse engineering and schema mapping [21] 36] are relevant to our work as well. Most database reverse engineering research attempts to map a relational schema to an object schema, or the transformation of relational queries to objectoriented queries [9][12] In our case, we translate SQL expressions from database application to object wrappers of the relational database. Compared with the work in query rewriting and view selection, we have several contributions as well. First, we proposed a new applications area for query rewriting and view ....

Chang, Y., Raschid, L. and Dorr, B., Transforming queries from a relational schema to an equivalent object schema: a prototype based on F-logic, Proceedings of the International Symposium on Methodologies for Intelligent Systems, 1994.

....of Datalog extended with semantic oid s . MSL uses information provided by wrappers, which represent their data in the Object Exchange Model (OEM) Due to its object oriented features, F logic may also be used for information integration and mediation: some approaches use F logic directly, e.g. CRD94, LBT92] whereas others use specialized variants [LSS93] 2. THE DOOD FRAMEWORK OF FLORID Florid 1 is a prototypical deductive object oriented database system, which has been recently extended to provide declarative rule based access for querying the Web [HLLS97, HLLS98] Florid s formal ....

Y. Chang, L. Raschid, and B. Dorr. Transforming Queries from a Relational Schema to an Equivalent Object Schema: A Prototype Based on F-Logic. In International Symposium on Methodologies in Information Systems, (ISMIS), number 869 in LNCS, pp. 154--163. Springer, 1994.

....namely the problem of handling semi structured data which naturally appears in the Web context. One major part of this problem is to integrate heterogeneous data from different sources. Due to its meta features, F logic is well suited to such tasks and has been already used for it, see e.g. CRD94] In future research, we will investigate the handling of semistructured data in F logic, which would allow to join the above mentioned two streams of research into a common framework. ....

Y. Chang, L. Raschid, and B. Dorr. Transforming queries from a relational schema to an equivalent object schema: a prototype based on F-logic. In International Symposium on Methodologies in Information Systems, (ISMIS94) , October 1994.

....inheritance, etc. and a powerful rule language. It has its roots in AI (frame based knowledge representation) and deductive object oriented databases. Apart from pure database modeling and querying, it has been applied in several related (but different) areas, including schema transformation [CRD94] information integration [GBMS99] querying the Web [LHL 98, MHLL99, DFKR99] knowledge representation reasoning with ontologies [DEFS99] and management of semistructured data [LHL 98] F logic extends Datalog and firstorder logic (including Skolem functions) In particular, well known ....

Y. Chang, L. Raschid, and B. Dorr. Transforming Queries from a Relational Schema to an Equivalent Object Schema: A Prototype Based on F-Logic. In Intl. Symposium on Methodologies in Information Systems, (ISMIS), LNCS 869, pp. 154--163. Springer, 1994.

....uniform handling of schema and data on the same level is essential. To describe heterogenous databases some recent proposals use specialized languages [7, 12] Interestingly, the main concepts of such languages are strongly related to those of F logic. Other approaches directly apply F logic [1, 13]. We introduce F logic and FLORID by presenting a (simple) example concerning problems of schema integration. However, we stress that FLORID is not specialized for that purpose but a full fledged system for arbitrary database applications. The example takes advantage from a distinctive feature of ....

Y. Chang, L. Raschid, and B. Dorr. Transforming queries from a relational schema to an equivalent object schema: a prototype based on F-logic. In International Symposium on Methodologies in Information Systems, (ISMIS-94), Oct. 1994.

....the management of large quantities of heterogeneous multimedia information using repository wrappers. The SIMS project [2, 3] uses the LOOM knowledge representation system as the data model and query language to implement the agent based integration. Other examples include University of Maryland [13, 19] and SRI [46] which in different ways integrate heterogeneous data and knowledge bases using a multiple F logic object schema, via the KIF knowledge interchange logic. The DIOM architecture is motivated mainly by the mediator architecture. For example, this architecture incorporates the notion of ....

Y. Chang, L. Raschid, and B. Dorr. Transforming queries from a relational schema to an equivalent object schema: a prototype based on f-logic. In Proceedings of the International Symposium on Methodologies in Information Systems (ISMIS), 1994.

....die Behandlung von Schema und Daten auf einer Ebene oft unverzichtbar. Zur Beschreibung der beteiligten Datenbanken verwenden manche neuere Ans atze spezialisierte Sprachen, die aber mit F Logik eng verwandt sind [13, 19] Andere Arbeiten setzen F Logik selbst ein, zumindest f ur Teile des Systems [4]. Um einen ersten Eindruck von F Logik und FLORID zu geben, w ahlen wir ein vereinfachtes Beispiel aus diesem Gebiet. Es sei aber betont, da FLORID kein spezialisiertes System darstellt, sondern als Umgebung f ur beliebige Datenbankanwendungen konzipiert wurde. Das Beispiel nutzt ausgiebig die M ....

Y. Chang, L. Raschid, and B. Dorr. Transforming queries from a relational schema to an equivalent object schema: a prototype based on F-logic. In International Symposium on Methodologies in Information Systems, (ISMIS-94), Oct. 1994.

.... runs through two types of wrappers: an Oracle wrapper for structured data sources and a HTML wrapper for accessing unstructured or semi structured web data sources (e.g. WWW pages, NetNews articles) 4 Related Work Several systems (e.g. TSIMMIS [5] Garlic [2] CARNOT [4] SIMS [1] DISCO [3]) Information Manifold [7] for integrating multiple information sources are being built based on the mediator architecture [12] The key aspect distinguishing DIOM from the other systems is its emphasis on scalability and extensibility of the query services by promoting source independent query ....

Y. Chang, L. Raschid, and B. Dorr. Transforming queries from a relational schema to an equivalent object schema: a prototype based on f-logic. In Proceedings of the International Symposium on Methodologies in Information Systems (ISMIS), 1994.

....mediation systems are being built for providing uniform access over multiple information sources based on the mediator architecture [48] DIOM [26] is a prototype of the distributed information mediator systems. Other prototype systems include TSIMMIS [12] Garlic [4] CARNOT [6] SIMS [2] DISCO [5]) and Information Manifold [21] The key aspect distinguishing DIOM from the other systems is its emphasis on scalability and extensibility of the query services by promoting source independent query processing at the mediator level and by describing the content and capability description of each ....

Y. Chang, L. Raschid, and B. Dorr. Transforming queries from a relational schema to an equivalent object schema: a prototype based on f-logic. In Proceedings of the International Symposium on Methodologies in Information Systems (ISMIS), 1994.

....County uses the Knowledge Query and Manipulation Language (KQML) to integrate heterogeneous databases. The SIMS project [3, 2] uses the LOOM knowledge representation system as the data model and query language to implement the agent based integration. Other examples include University of Maryland [6, 7] and SRI [18] which in different ways integrate heterogeneous data and knowledge bases using multiple F logic object schema, via the KIF knowledge interchange logic. Among these projects, only a few have dealt with different aspects of the query processing and query optimization issues. For ....

Y. Chang, L. Raschid, and B. Dorr. Transforming queries from a relational schema to an equivalent object schema: a prototype based on f-logic. In Proceedings of the International Symposium on Methodologies in Information Systems (ISMIS), 1994.

....treated as a knowledge source, to be used to provide explanations, etc. We use a high level logic language, F logic (see [Kifer and Lausen, 1989] Kifer et al. , 1990] Lawley, 1993] to express this knowledge. We outline this research in section 3, but refer the reader to details in [Chang,1995; Chang et al. , 1994; Raschid and Chang, 1994; Raschid et al. , 1994a; Raschid et al. , 1993] We also address the issue of query optimization in heterogeneous environments. We are concerned with the problem of modifying traditional query optimization techniques so they may be applied to the task of producing ....

....be used to provide explanations, etc. We use a high level logic language, F logic (see [Kifer and Lausen, 1989] Kifer et al. , 1990] Lawley, 1993] to express this knowledge. We outline this research in section 3, but refer the reader to details in [Chang,1995; Chang et al. , 1994; Raschid and Chang, 1994; Raschid et al. , 1994a; Raschid et al. , 1993] We also address the issue of query optimization in heterogeneous environments. We are concerned with the problem of modifying traditional query optimization techniques so they may be applied to the task of producing optimized mediated queries. There has been little ....

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Chang, Y., Raschid, L. and Dorr, B. (1994) "Transforming queries from a relational schema to an equivalent object schema: a prototype based on F-logic," Proceedings of the International Symposium on Methodologies for Intelligent Systems.

....resolve representational heterogeneity between schema, and also consider the syntax of each query language. The interoperation between object and relational queries was initially described in Raschid et al.(1993, 1994) and the interoperation from relational to object queries has been presented in Chang et al.(1994). Details of the canonical representation to resolve representational heterogeneity among schemas has been presented in Chang and Raschid (1995) In this paper, we provide a detailed description of the interoperability between object and relational queries. The paper is structured as follows: In ....

....group of rules resolve the class hierarchy conflict. When mapping from relational schema to object schema, these rules will use the key inclusion dependencies among relations to determine the inclusion relationship between them and identify the relevant class hierarchies in the object schema (see Chang et al. (1994)) When mapping from object schema to relational schema, these rules will produce a sequence of joins for the relational query, corresponding to inheritance through a class hierarchy in the object schema (see Raschid et al.(1993,1994) Selected rules in each group will be applied, and each ....

[Article contains additional citation context not shown here]

Chang, Y., Raschid, L. and Dorr, B.J. (1994) "Transforming queries from a relational schema to an equivalent object schema: a prototype based on F-logic," Proceedings of the International Symposium on Methodologies in Information Systems, (ISMIS-94).

....the context of our mapping approach. In section 3.2 , we introduce the two parameterized canonical representations for classifying and resolving heterogeneities in query languages and schemas. The representations are extensions to a previous solution described by Raschid et al. 1993, 1994) and Chang et al. 1994) These allow us to accept more complex queries and also to resolve more conflicts that was previously possible. In section 3.3, we describe the architecture for supporting interoperability. The extractor module (EM) and heterogeneous mapping module (HTM) will be discussed in detail. We will ....

....approach. We make use of a higher order logical language (F logic) which has higher order syntactical structures but first order semantics, to express both of these canonical representations. In our research, we will extend the canonical representation proposed in Raschid et al. 1993, 1994) and Chang et al. 1994). These extensions will allow the representation and transformation of more expressive SQL queries than those of Chang et al. 1994) and more expressive XSQL language queries than were considered in Raschid et al. 1993, 1994) It will also extend the types of conflicts that can be resolved, for ....

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Chang, Y., Raschid, L. and Dorr, B. (1994) "Transforming queries from a relational schema to an equivalent object schema: a prototype based on F-logic," Submitted to the International Symposium on Methodologies for Intelligent Systems.

.... Hwang (1984) Pegasus [Ahmed et al. (1991) Albert et al. (1993) UniSQL M [Kim et al. (1993) Kim and Seo (1992) SIMS [Arens and Knoblock (1992) Arens et al. (1993) Alternative approaches either specify a canonical mediator knowledge base which has mapping knowledge among different schema [Chang et al. (1994), Qian (1993) Qian and Raschid (1995) Raschid et al. (1993) Raschid and Chang (1994) or advocate the federated approach, as summarized in [Sheth and Larson (1990) There has also been research on constructing a calibrating database, to develop cost models which capture the various parameters ....

.... Kim and Seo (1992) SIMS [Arens and Knoblock (1992) Arens et al. (1993) Alternative approaches either specify a canonical mediator knowledge base which has mapping knowledge among different schema [Chang et al. (1994) Qian (1993) Qian and Raschid (1995) Raschid et al. (1993) Raschid and Chang (1994)] or advocate the federated approach, as summarized in [Sheth and Larson (1990) There has also been research on constructing a calibrating database, to develop cost models which capture the various parameters corresponding to HDBMS [Du et al. (1992) This study assumes that the first step of ....

Chang, Y., Raschid, L. and Dorr, B.J. (1994) "Transforming queries from a relational schema to an equivalent object schema: a prototype based on F-logic," Proc. of the ISMIS-94 International Symposium.

....group of rules resolve the class hierarchy conflict. When mapping from relational schema to object schema, these rules will use the key inclusion dependencies among relations to determine the inclusion relationship between them and identify the relevant class hierarchies in the object schema (see [Cha94b]) When mapping from object schema to relational schema, these rules will produce a sequence of join for the relational query corresponding to inheritance through a class hierarchy in the object schema (see [Ras93, 94] Selected rules in each group will be applied, and each produces a part of the ....

....in the format relation name.attributename. The parameter from represents information in the from clause of the SQL query. The parameter reference represents each join over a foreign key. The parameter identification corresponds to the selection of attribute values equal to a constant. Please see [Cha94b] for more details) The mapping rules in HTM then translate the CRrel to the corresponding TQobj (transformed query for object model) Details of TQobj are discussed in [Cha94b] We only describe two parameters of TQobj here. One parameter is sub class which returns the most specific class label ....

[Article contains additional citation context not shown here]

Chang, Y., Raschid, L. and Dorr, B. "Transforming queries from a relational schema to an equivalent object schema: a prototype based on F-logic," Proceedings of the International Symposium on Methodologies for Intelligent Systems, 1994.

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