Schema Update Research Articles

An Algorithm for Transforming Property Path Query Based on Shape Expression Schema Update

An Algorithm for Transforming Property Path Query Based on Shape Expression Schema Update

Research on Updating of Body Schema Using AR Limb and Measurement of the Updated Value

The body schema, an internal model in the brain used to recall the body position, is known to be updated by adapting to the changes in the body figure due to the body growth. Furthermore, the recent research has reported the active updating of the body schema by misunderstanding one's body position using the illusion phenomenon. However, the current method of actively updating the body schema has limited effects and does not handle selective updating of each body part. Therefore, in this paper, a new method using an augmented reality (AR) limb is proposed for the selective updating of unitary parts of the body image in a short period of time. The AR limb is the virtual limb composed by actively extendable and retractable parts, projected by head-mounted display. The basic concept is that the body schema is updated to match the extended and retracted part of the AR limb based on the body schema learning mechanism in the sensory integration of visual and somatic information. The potential effectiveness of the method was verified by actual experiment applying the body schema update to the right forearm.

CRIUS

Non-technical users are increasingly adding structures to their data. This gives rise to the need for database design. However, traditional database design is deliberate and heavy-weight, requiring technical expertise that everyday users may not possess. For this reason, we propose that users of personal data management applications should be able to create and refine data structures in an ad-hoc way over time, thereby "organically" growing their schemas. For this purpose, we develop a spreadsheet-like direct manipulation interface. We show how integrity constraints can still provide value, even in this scenario of frequent schema and data modifications. We also develop a back-end database implementation to support this interface, with a design that permits schema changes at a low cost.We have folded these ideas into a system, called CRIUS, which supports a nested data model and a graphical user interface. From the user's perspective, the chief advantages of CRIUS are its support for simple schema definition and modification through an intuitive drag-and-drop interface, as well as its guidance towards user data entry based on incrementally updated data integrity. We have evaluated CRIUS by means of user studies and performance studies. The user studies indicate that 1) CRIUS makes it much easier for users to design a database, as compared to state-of-the-art GUI database design tools, and 2) CRIUS makes user data entry more efficient and less error-prone. The performance experiments show that 1) the incremental integrity update in CRIUS is very efficient, making the data entry guidance applicable and 2) the backend database implementation in CRIUS significantly improves the performance of schema update tasks, without a significant impact on other operations.

On the abductive or deductive nature of database schema validation and update processing problems

We show that database schema validation and update processing problems such as view updating, materialized view maintenance, integrity constraint checking, integrity constraint maintenance or condition monitoring can be classified as problems of either abductive or deductive nature, according to the reasoning paradigm that inherently suites them. This is done by performing abductive and deductive reasoning on the event rules (Olive 1991), a set of rules that define the difference between consecutive database states. In this way, we show that it is possible to provide methods able to deal with all these problems as a whole. We also show how some existing general deductive and abductive procedures may be used to reason on the event rules. In this way, we show that these procedures can deal with all database schema validation and update processing problems considered in this paper.

Rich Base Schema

In this paper, we propose a model of schema versions for object-oriented databases called RiBS. At the heart of this model is the concept of the Rich Base Schema (RiBS). Each schema version is in the form of a class hierarchy view over one base schema, RiBS, which accumulates all the schema information ever defined in the schema versions. Users, insulated from RiBS layer, access databases only through schema versions. Users impose schema evolution directly on schema versions, and the effects are, if necessary, automatically propagated to RiBS. We first describe the structure of the model and then introduce a set of invariants that should be satisfied by the model structure. As the third element of our model, we give a set of schema update operations, of which semantics are defined so as to preserve all the invariants.

A model of schema versions for object-oriented databases based on the concept of rich base schema

In this paper, we propose a model of schema versions for object-oriented databases called RiBS. At the heart of this model is the concept of the rich base schema called (RiBS). In our model, each schema version is in the form of a class hierarchy view over one base schema, called RiBS, which has richer schema information than any existing schema version in the database. Users are supposed to be concerned only with schema versions. Direct schema updates on schema versions are allowed, and their effects are, if necessary, automatically propagated to RiBS. We first describe the structural part of the model and then introduce a set of invariants that should always be satisfied by structural parts. As the third element of our model, we give a set of schema update operations, the semantics of which are defined, so as to preserve all the invariants. Another contribution of this paper is the work on schema-version-merging within the RiBS model. We identify several conflicts in schema-version-merging, and then provide a semi-automatic schema-version-merging algorithm to resolve these conflicts. This algorithm is semi-automatic in the sense that it requires minimal user involvement during schema-version-merging.

ARCADIA: A System for the Integration of Angiocardiographic Data and Images by an Object-Oriented DBMS

Use of data base techniques to store medical records has been going on for more than 40 years. Some aspects still remain unresolved, e.g., the management of textual data and image data within a single system. Object-orientation techniques applied to a database management system (DBMS) allow the definition of suitable data structures (e.g., to store digital images): some facilities allow the use of predefined structures when defining new ones. Currently available object-oriented DBMS, however, still need improvements both in the schema update and in the query facilities. This paper describes a prototype of a medical record that includes some multimedia features, managing both textual and image data. The prototype here described considers data from the medical records of patients subjected to percutaneous transluminal coronary artery angioplasty. We developed it on a Sun workstation with a Unix operating system and ONTOS as an object-oriented DBMS.