3. INTRODUCTION
A temporal database is a database that has certain features that
support time-sensitive status for entries.
Temporal database stores data relating to time instances. It
offers temporal data types and stores information relating to
past, present and future time.
More specifically the temporal aspects usually include Valid time
and Transaction time. These attributes can combined to form
bitemporal data
4. PROBLEM DEFINITION
Schema versioning is one of a number of related areas dealing with the same
general problem—that of using multiple heterogeneous schemata for various
database related tasks.
In particular, schema versioning, and its weaker companion, schema
evolution, deal with the need to retain current data and software system
functionality in the face of changing database structure. Schema versioning
and schema evolution offer a solution to the problem by enabling intelligent
handling of any temporal mismatch between data and data structure. This
survey discusses the modelling, architectural and query language issues
relating to the support of evolving schemata in database systems. An
indication of the future directions of schema versioning research is also given.
5. ADVANTAGES AND DISADVANTAGES
Advantages:
1)
Allows high level declarative query language.
2)
Provides a formal framework to solve outstanding problems in temporal
databases,
a)interoperability of different data models
b)functional dependencies and normal form.
Disadvantages:
1)Its related to database store for a given timestamps so there is more
storage reqd. Of storage media than simple conventional database.
2)Its very likely to loss necessary information from the database if you forget
to create alt. downloads or storage
7. CURRENT RESEARCH
Spatiotemporal database management systems can become an
enabling technology for important applications such as
Geographic Information Systems (GIS), environmental information
systems, and multimedia. In this paper we address research
issues in spatial-temporal databases, by providing an analysis of
the challenges set, the problems encountered, as well as the
proposed solutions and the envisioned research areas open to
investigation.
8. CONCLUSION
Temporal database seems an emerging concept dealing
with data storage in a scheduled manner. much more
bigger efforts are made to generalize the growing data and
the database structure to be changed in due time.
We need to proceed with time and to keep an eye on
particular data storage trends for better use.