In this paper, a systematic method for evaluating queries issued to an federated relational database system is presented. The method consists of four phases: syntactic analysis, query decomposition, query translation and result synthesis, which all can be done automatically based on the metadata built in the system, even if the structure conflicts among the local databases exist.

The paper presents a: a) brief overview and analysis of existing approaches to the data warehouse (DW) evolution problem, and b) detailed description of the research idea for the DW evolution problem (primarily intended for structured data sources and realizations with relational database engines). We observe the DW evolution problem as a double issue from the DW perspective, and from the maste...

We investigated the problems of support of XML databases. An extensible data model appears as a result of this research. The offered data model is considered as an XML application. Our approach of support of XML databases is an attempt to create a data model which is based on the XML data model and combines the best features of the relational and object databases. To model the database concepts...

Electronic learning objects (LOs) are commonly conceived of as digital units of information used for teaching and learning. To facilitate their classification for pedagogical planning and retrieval purposes, LOs are complemented with metadata (e.g., the author). These metadata are usually restricted by a set of predetermined tags to which the classification schema must conform (e.g., IEEE LOM)....

We discuss long-term preservation of and access to relational databases. The focus is on national archives and science data archives which have to ingest and integrate data from a broad spectrum of vendor-specific relational database management systems (RDBMS). Furthermore, we present our solution SIARD which analyzes and extracts data and data logic from almost any RDBMS. It enables, to a reas...

The CenSSIS Image Database is a scientific database that enables effective data management and collaboration to accelerate fundamental research. This paper describes the design and use of a state-of-the-art relational image database management system, accessible through a standard web-browser interface. The application utilizes a robust security architecture and is designed for efficient data s...

This paper describes a content object and metadata repositories model, which provides an alternative to search and to access repositories developed in Colombia and Latin America. Along with the repositories model, an initial design of a decision support system for repositories is presented. In order to preserve the autonomy of each repository, a common web services interface is considered. This...

This paper presents an approach for dynamically generating and processing user input form variants from metadata stored in a database. Many web-based applications utilize a series of similar looking input forms as a basis for capturing information from users, such as for surveys, cataloging, etc. Typical approaches for form generation utilize static HTML pages or dynamic pages generated program...

Nowadays, data can be represented and stored by using different formats ranging from non structured data, typical of file systems, to semistructured data, typical of Web sources, to highly structured data, typical of relational database systems. Therefore, the necessity arises to define new models and approaches for uniformly handling datasources having different formats and structures, and obt...

In recent years, middleware industry, and particularly the CORBA project, have strongly integrated several aspects derived from databases: persistence, transaction management, security, etc. However, there still is a conceptual ”impedance mismatch” between the CORBA concepts and the concepts used in connection with databases (often referred to as a foundation of persistence). Bridging this gap ...