Database Reference
In-Depth Information
Database:
A collection of persistent data. In a database, data are modeled in accordance with a
database model. This model defines the structure of the data, the constraints for integrity and security,
and the behavior of the data.
Fuzzy Query:
A database query which involves imprecisely specified search conditions. These
conditions are often expressed using terms of a natural language which are modeled using fuzzy logic.
Linguistic Quantifier:
a natural language expression such as ¨most¨, around 5¨ which expresses an
imprecise proportion or quantity.
Linguistic Summary of Data:
a linguistic (by a sentence or a small number of sentences in a natural
language) summarization of a set of data.
Protoform:
an abstract prototype of a linguistically quantified proposition, i.e. of an expression such
as ¨Most employees are young¨.
Relational Database:
A relational database is a database that is modeled in accordance with the
relational database model. In the relational database model, the data are structured in relations that are
represented by tables. The behavior of the data is defined in terms of the relational algebra, which origi-
nally consists of eight operators (union, intersection, division, cross product, join, selection, projection
and division), or in terms of the relational calculus, which is of a declarative nature.
