Temporal databases introduce the concept of time into underlying data, and provide built-in facilities that allow users to store and retrieve time-varying data. The aggregation in temporal databases, that is, temporal aggregation is an extension of conventional aggregation on the domain and range of aggregates to include time concept. Temporal aggregation is important for various applications, ...

In reality, some objects or concepts have properties with a time-variant or time-related nature. Modelling these kinds of objects or concepts in a (relational) database schema is possible, but time-variant and time-related attributes have an impact on the consistency of the entire database. Therefore, temporal database models have been proposed to deal with this. Time itself can be at the sourc...

Most modern database applications involve a significant amount of time dependent data and a substantial proportion of this data is now-relative, current now. While a lot of work has focussed on indexing on temporal data in general, only a little work has addressed the indexing of now-relative data, which is a natural and meaningful part of every temporal database as well as being the focus of m...

∃! Τ name(T) = name(X) + "_" + name(rel(x,y)) + "_" + name(Y) ∧ ∃! F1 ∈ Τ name(F1) = name(X) + "$" ∧ ∃! F2 ∈ Τ (is_entity(Y) → name(F2) = name(Y) + "$" ∨ is_value(Y) → name(F2) = name(Y)) ∧ ∃! F3 ∈ Τ name(F3) = name(validity_period(rel(X,Y))) + "$" ∧ is_entity(X) ∃! Τ name(T) = name(X) + "_" + name(rel(x,y)) + "_" + name(Y) ∧ ∃! F1 ∈ Τ name(F1) = name(X) + "$" ∧ ∃! F2 ∈ Τ (is_entity(Y) → name(F...

┌──────────────────────────────────────────────────────┐ │

In a temporal object oriented database TOODB not only the actual state but also some parts of the history are stored We identify some problems for the consistency of the database and the update operations in a bitemporal environment We propose a strategy how a database which is only partially temporal can be interpreted intensionally as a temporal database Additionally we analyze some related w...

A temporal database management system is being considered as an important DBMS in new database applications such as engineering databases, VLSI, and CAD. Much researche on temporal databases, temporal query languages and temporal modeling techniques have been proposed. However, thus researche has not considered the schema modification problem in a temporal database yet. In this paper, we propos...

Support of collaborative work and management of spatio-temporal data has become one of the most interesting and important database applications, which is due to the tremendous progress of database and its surrounding technologies in the last decade. In this paper, we investigate the new generation database technologies that are needed to support such advanced applications. Because of the recent...

In this article we deal with the problem of using temporal knowledge in the specification of the dynamics of a database. Temporal knowledge is formalized with formulas that refer to the evolution of the database. In the article we analyze several problems involving temporal knowledge: (1) Specification of complex temporal preconditions for database transactions. (2) Specification and maintenanc...