A framework for multi-tier type evolution and data migration

This paper describes a framework that supports the simultaneous evolution of objectoriented data models and relational schemas with respect to a tool- supported object-relational mapping. Thereby the proposed framework accounts for non-trivial data migration induced by type evolution from the outset. The support for data migration is offered on the level of transparent data access. The framework consists of the following integrated parts: an automatic model change detection mechanism, a generator for schema evolution code and a generator for data migration APIs. The framework has been concepted in the IMIS project. IMIS is an information system for environmental radioactivity measurements. Though the indicated domain especially demands a solution like the one discussed in the paper, the achievements are of general purpose for multi-tier system architectures with object-relational mapping

Towards a constructional approach to discourse-level phenomena : the case of the Spanish interpersonal epistemic stance construction

This study contributes to a better understanding of how constructional models can be applied to discourse-level phenomena, and constitute a valuable complementation to previous grammaticalization accounts of pragmatic markers. The case study that is presented concerns the recent development of the interpersonal epistemic stance construction in Spanish. The central argument is that the expanding use of sabes as a pragmatic marker can best be fully understood by taking into account the composite network of related expressions which Spanish speakers have at their disposal when performing a particular speech act. The diachronic analysis is documented with spoken corpus examples collected in recent decades, and is mainly informed by frequency data measuring the productivity, as well as formal properties of the construction and its instances

Ordering Things: The Irish State Administration Database

New theoretical approaches to the state have posed challenges for the comparative analysis of the organizational features of states. The analysis of state bodies and state agencies has largely been confined to the sub-discipline of public administration, and has been resistant to the systematic classification that has made progress possible in other areas of comparative politics. This article argues that there is much to be gained by reconceptualizing state bodies in a comparative context. This paper profiles the classification system underlying the construction of the Irish State Administration Database (ISAD) (Hardiman et al., 2011). This paper sets out a new approach to conceptualizing the organizational and functional features of states. ISAD not only provides a valuable research resource for work on the Irish state, but can also provide a framework for building a comparative research agenda.

The schema coercion problem

Journal ArticleOver the past decade, the ability to incorporate data from a wide variety of sources has become increasingly important to database users. To meet this need, significant effort has been expended in automatic database schema manipulation. However, to date this effort has focused on two aspects of this problem: schema integration and schema evolution. Schema integration results in a unified view of several databases, while schema evolution enhances an existing database design to represent additional information. This work defines and addresses a third problem, schema coercion, which defines a mapping from one database to another. This paper presents an overview of the problems associated with schema coercion and how they correspond to the problems encountered by schema integration and schema evolution. In addition, our approach to this problem is outlined. The feasibility of this approach is demonstrated by a tool which reduces the human interaction required at all steps in the integration process. The database schemata are automatically read and converted into corresponding ER representations. Then, a correspondence identification heuristic is used to identify similar concepts, and create mappings between them. Finally, a program is generated to perform the data transfer. This tool has successfully been used to coerce the Haemophilus and Methanococcus genomes from the Genbank ASN.l database to the Utah Center for Human Genome Research database. Our comprehensive approach to addressing the schema coercion problem has proven extremely valuable in reducing the interaction required to define coercions, particularly when the heuristics are unsuccessful

A 2-dimensional Geometry for Biological Time

This paper proposes an abstract mathematical frame for describing some features of biological time. The key point is that usual physical (linear) representation of time is insufficient, in our view, for the understanding key phenomena of life, such as rhythms, both physical (circadian, seasonal ...) and properly biological (heart beating, respiration, metabolic ...). In particular, the role of biological rhythms do not seem to have any counterpart in mathematical formalization of physical clocks, which are based on frequencies along the usual (possibly thermodynamical, thus oriented) time. We then suggest a functional representation of biological time by a 2-dimensional manifold as a mathematical frame for accommodating autonomous biological rhythms. The "visual" representation of rhythms so obtained, in particular heart beatings, will provide, by a few examples, hints towards possible applications of our approach to the understanding of interspecific differences or intraspecific pathologies. The 3-dimensional embedding space, needed for purely mathematical reasons, allows to introduce a suitable extra-dimension for "representation time", with a cognitive significance.Comment: Presented in an invited Lecture, conference "Biologie e selezioni naturali", Florence, December 4-8, 200

A database model for object dynamics.

Object-oriented database systems, Dynamic object re-classification, Object role model, Dynamic class hierarchy, Object migration

A Model for Compound Type Changes Encountered in Schema Evolution

Schema evolution is a problem that is faced by long-lived data. When a schema changes, existing persistent data can become inaccessible unless the database system provides mechanisms to access data created with previous versions of the schema. Most existing systems that support schema evolution focus on changes local to individual types within the schema, thereby limiting the changes that the database maintainer can perform. We have developed a model of type changes incorporating changes local to individual types as well as compound changes involving multiple types. The model describes both type changes and their impact on data by defining derivation rules to initialize new data based on the existing data. The derivation rules can describe local and nonlocal changes to types to capture the intent of a large class of type change operations. We have built a system called Tess (Type Evolution Software System) that uses this model to recognize type changes by comparing schemas and then produces a transformer that can update data in a database to correspond to a newer version of the schema

A temporal versioned object-oriented data schema model

AbstractThis paper describes in a formal way a data schema model which introduces temporal and versioning schema features in an object-oriented environment. In our model, the schema is time dependent and the history of the changes which occur on its elements are kept into version hierarchies. A fundamental assumption behind our approach is that a new schema specification should not define a new database, so that previous schema definitions are considered as alternative design specifications, and consequently, existing data can be accessed in a consistent way using any of the defined schemas