The notion of H-IFS -an approach for enhancing query capabilities in Oracle10g

Query answering requirements for a knowledge based treatment of user requests led us to introduce the concept of closure of an Intuitionistic fuzzy set over a universe that has a hierarchical structure. We introduce the automatic analysis of queries according to concepts defined as part of a knowledge based hierarchy in order to guide the query answering as part of an integrated database environment with the aid of hierarchical Intuitionistic fuzzy sets, H-IFS. In this paper based on the notion of H-IFS we propose an ad-hoc utility build on top of Oracle10g that allows us to enhance the query capabilities of by providing better and knowledgeable answers to user’s requests. The theoretical aspects as well the practical issues and achieved results are presented throughout the rest of the paper

Treatment of imprecision in data repositories with the aid of KNOLAP

Traditional data repositories introduced for the needs of business processing, typically focus on the storage and querying of crisp domains of data. As a result, current commercial data repositories have no facilities for either storing or querying imprecise/ approximate data. No significant attempt has been made for a generic and applicationindependent representation of value imprecision mainly as a property of axes of analysis and also as part of dynamic environment, where potential users may wish to define their “own” axes of analysis for querying either precise or imprecise facts. In such cases, measured values and facts are characterised by descriptive values drawn from a number of dimensions, whereas values of a dimension are organised as hierarchical levels. A solution named H-IFS is presented that allows the representation of flexible hierarchies as part of the dimension structures. An extended multidimensional model named IF-Cube is put forward, which allows the representation of imprecision in facts and dimensions and answering of queries based on imprecise hierarchical preferences. Based on the H-IFS and IF-Cube concepts, a post relational OLAP environment is delivered, the implementation of which is DBMS independent and its performance solely dependent on the underlying DBMS engine

Lattice-structured Domains, Imperfect Data and Inductive Queries

. The relational model, as proposed by Codd, contained the concept of relations as tables composed of tuples of single valued attributes taken from a domain. In most of the early literature this domain was assumed to consist of elementary items such as simple (atomic) values, dened complex data types or arbitrary length binary objects. Subsequent to that the nested relational or non-rst normal form model allowing set-valued or relation-valued attributes was proposed. Within this model an attribute could take multiple values or complete relations as values. This paper presents a further extension to the relational model which allows domains to be dened as a hierarchy (specically a lattice) of concepts, shows how dierent types of imperfect knowledge can be represented in attributes dened over such domains, and demonstrates how lattices allow the accommodation of some forms of inductive queries. While our model is applied to at relations, many of the results given are applicable also to nested relations. Necessary extensions to the relational algebra and SQL, a justication for the extension in terms of application areas and future research areas are also discussed.