Search results for "Database theory"

Migration of Relational Database to Document-Oriented Database: Structure Denormalization and Data Transformation

2015

Relational databases remain the leading data storage technology. Nevertheless, many companies want to reduce operating expenses, to make scalable applications that use cloud computing technologies. Use of NoSQL database is one of the possible solutions, and it is forecasted that the NoSQL market will be growing at a CAGR of approximately 50 percent over the next five years. The paper offers a solution for quick data migration from a relational database into a document-oriented database. We have created semi-automatically two logical levels over physical data. Users can refine generated logical data model and configure data migration template for each needed document. Data migration features…

PDB: A pictorial database oriented to data analysis

1993

The paper describes a new pictorial database oriented to image analysis, implemented inside the MIDAS data analysis system. Pictorial databases need expressive data structures in order to represent a wide class of information from the numerical to the visual. The model of the database is relational; however, a full normalization is not achievable, owing to the complexity of the visual information. The paper reports the general design and notes on the software implementation. Preliminary experiments show the performance of the pictorial database. Copyright © 1993 John Wiley & Sons, Ltd

The Natural Order-Generic Collapse for ω-Representable Databases over the Rational and the Real Ordered Group

2001

We consider order-generic queries, i.e., queries which commute with every order-preserving automorphism of a structure's universe. It is well-known that first-order logic has the natural order-generic collapse over the rational and the real ordered group for the class of dense order constraint databases (also known as finitely representable databases). I.e., on this class of databases over 〈Q, <〉 or 〈R, <〉, addition does not add to the expressive power of first-order logic for defining order-generic queries. In the present paper we develop a natural generalization of the notion of finitely representable databases, where an arbitrary (i.e. possibly infinite) number of regions is allowed. We …

First-order expressibility of languages with neutral letters or: The Crane Beach conjecture

2005

A language L over an alphabet A is said to have a neutral letter if there is a letter [email protected]?A such that inserting or deleting e's from any word in A^* does not change its membership or non-membership in L. The presence of a neutral letter affects the definability of a language in first-order logic. It was conjectured that it renders all numerical predicates apart from the order predicate useless, i.e., that if a language L with a neutral letter is not definable in first-order logic with linear order, then it is not definable in first-order logic with any set N of numerical predicates. Named after the location of its first, flawed, proof this conjecture is called the Crane Beach …

An Ehrenfeucht-Fraïssé Approach to Collapse Results for First-Order Queries over Embedded Databases

2001

We present a new proof technique for collapse results for first-order queries on databases which are embedded in N or R>o. Our proofs are by means of an explicitly constructed winning strategy for Duplicator in an Ehrenfeucht-FraissE game, and can deal with certain infinite databases where previous, highly involved methods fail. Our main result is that first-order logic has the natural-generic collapse over {N,≤ ,+} for arbitrary (i.e., possibly infinite) databases. Furthermore, a first application of this result shows the natural-generic collapse of first-order logic over {R>o,≤,+} for a certain kind of databases over R>o which consist of a possibly infinite number of regions.

Contributions from ADBIS 2018 workshops

2018

The ADBIS conferences provide an international forum for the presentation of research on database theory, development of advanced DBMS technologies, and their applications. The 22nd edition of ADBIS, held on September 2–5, 2018, in Budapest, Hungary, includes six thematic workshops collecting contributions from various domains representing new trends in the broad research areas of databases and information systems.

Databases and Information Systems

2001

Model independent assertions for integration of heterogeneous schemas

1992

Due to the proliferation of database applications, the integration of existing databases into a distributed or federated system is one of the major challenges in responding to enterprises' information requirements. Some proposed integration techniques aim at providing database administrators (DBAs) with a view definition language they can use to build the desired integrated schema. These techniques leave to the DBA the responsibility of appropriately restructuring schema elements from existing local schemas and of solving inter-schema conflicts. This paper investigates the assertion-based approach, in which the DBA's action is limited to pointing out corresponding elements in the schemas an…

ENFORCEMENT OF INTER-TASK DEPENDENCIES IN WORKFLOWS, CHARACTERIZATION AND PARADIGM

1998

Workflow techniques have gained a lot of attention as a means to support advanced business applications such as cooperative information systems and process re-engineering but also as a means to integrate legacy systems. Inter-task dependencies, described separately from the other parts of the workflow, have been recognized as a valuable method in describing certain restrictions on the executions of workflows. In this paper, we study the issue of pre-analysing and enforcing inter-task dependencies. The protocol and the theory behind it are presented, along with examples and discussions on ways to improve the performance. The idea is to present the meaning of a dependency through an automato…