Essay about A Model Theory for General Schema Administration Models


A Model Theory for Generic Schema Supervision Models

Kinan M Ing Haffar

UM4699SIT10550D 07/08/2007


The core of a model theory for generic schizzo management can be developed. This theory provides two distinctive features: that applies to a number of categories of schemas, and that applies to changes of both the schema framework and its ethics constraints. A subtle difficulty of programa integration is known as in its basic form, not bound to virtually any particular class of schemas. The proposed answer, as well as the general theory, is based entirely upon schema morphisms that hold both structural and semantic properties. Mix and match results that apply to the two levels (i. e., the schema plus the data levels) are established. These effects lead to the main contribution of this paper: an official schema and data administration framework intended for generic schizzo management. Implications of this theory are established that apply at integrity complications in programa integration. The theory is illustrated by a particular category of schemas with object-oriented features along with typical database honesty constraints.



This kind of paper shows the core results of a model theory for generic schema managing, by which we mean programa and database transformation capabilities that are self-employed of a particular data version. Such transformations require major database encoding tasks, such as integrating source schemas when building a info warehouse or integrating different user views into a general database programa. In spite of nontrivial typing concerns created simply by such transformations, database coding and other relevant paradigms have been primarily fitted to dealing with strength aspects of these transformations. A serious challenge is in properly dealing with semantics: the integrity limitations associated with data source schemas. The second major obstacle is in developing such an auto dvd unit theory that is certainly applicable to a variety of data models, such as the relational, object-oriented, and XML models [23]. This really is challenging mainly because schemas and their underlying databases are very distinct in these 3 major categories of models similar to languages and the underlying logics used for revealing the ethics constraints. On the pragmatic part, generic schema management procedures and equipment have been regarded as in [4], and more specific system implications in [5, 20]. These types of papers argue that many hard and expensive database coding problems require the treatment of mappings between schemas. Examples will be populating a data warehouse by data options, exposing a collection of data sources as a built-in schema, making a web site wrapper, generating an object-oriented wrapper for relational data, and mapping a great XML schema to a relational schema. Inspite of many commonalities of these schema management challenges, tools and languages are normally engineered to get only one malocclusion. A more appealing approach would be to build universal schema administration tools and languages that will apply to many of these problems, with only several customization required for the data style and difficulty at hand. The formal available problem is to find a suitable model theory that would be able to manage this generality. Our proposed model theory has a specific flavor, described in the make use of arrows that appear in two amounts. At the coto level the arrows symbolize schema conversions. For example , a great arrow can map a data source schizzo to a data warehouse schema, or two arrows could map each of two databases schemas into a mediated programa. These changes are thought as schema morphisms that map the strength properties and integrity constraints of a schema. At the data level the arrows are data conversions specified because database morphisms. Database morphisms map using the data makes its presence felt a manner that may be compatible with the operations on those models and that preserves the schema's...

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