Database
We, people, use databases more often than what we could think. Every time we have to complete an information research or query, the use of database is necessary and it significantly improve your research skills, and allow you to save precious time. But what is really a database? Is it only in electronic form? This article will allow you to discover (or to learn more) about what database are, to analyze the different models pr types that exist, and the most famous database used today in electronic form.
I) Definition
The database is actually a used term for data storage in computer science. The concept basically refers to a collection of information organized in a common pool to provide efficient retrieval for one or more multiple uses. (Burtle Laura et al. 16) Indeed, organizing the different information you have enables you to find it more easily the next time. The result you get by organizing them is a database: an organized collection of information.
Database does not have to be in electronic form necessarily (Brenner Eric 1).It can be saved in various formats such as text, video and sound. For instance, in a library, an organized index of the titles of the books is a database. An alphabetical arrangement of names in an address book is database (phonebook, address books, dictionaries, calendar are some examples of common database).Sizes of the databases may vary a lot from a single file stored in the tables to very large databases containing several millions of records.
With the size of the amount of information present on the internet, the requirement of efficient databases is understandable. Different types, models exist, but the most important is to find the database that best fit with our query and that will enable us to improve our information research skills. In order to find that database, search engines can be used (Be careful not to merge the two!)
II) Models of Database
A database Model is the structure of a database. In other words, it is a way of structuring data, and it defines a set of operation that can be performed on the data. Various models exist, but we will describe only two of them. Hierarchical model:This model is very efficient, and used commonly for recipes, tables…In this model data are organised into a tree-like structure.
Relational model
This model contains various tables, each similar to the ´´flat model´´. The different tables are linked together, through values that are present in two different tables. In each table, information about a particular entity is represented in rows and columns. As a result, the relation refers to the various tables in a database. ("Database."1)
Other models that can be encountered:
Network model, Flat Model, Entity-relationship model, ,Object-relational model, Object Model.
III) Types of databases
1 End-user database: These databases consist of a variety of data files developed by end-users at their workstations. Examples of these are collections of documents in spreadsheets, word processing and even downloaded files.
2 External database: These databases provide access to external, privately-owned data online — available for a fee to end-users and organizations from commercial services. Access to a wealth of information from external database is available for a fee from commercial online services and with or without charge from many sources in the Internet.
3 Hypermedia databases on the web: These are a set of interconnected multimedia pages at a web-site. They consist of a home page and other hyperlinked pages of multimedia or mixed media such as text, graphic, photographic images, video clips, audio etc.
4 Navigational database: In navigational databases, queries find objects primarily by following references from other objects. Traditionally navigational interfaces are procedural, though one could characterize some modern systems like XPath as being simultaneously navigational and declarative.
5. Operational database: These databases contain full information on which the operations of an organization will be based on. They are also called subject-area databases (SADB), transaction databases, and production databases.
6. Analytical database: These databases contain information collected from external databases. The data use to be summed up. They are also known as multidimensional databases, management databases, or information databases.
7.Data warehouse: A data warehouse contain information from the years before. Directors and other people use it as it is a very important resource of information. Though data warehouse are fast to recover, they load very slowly.
8.Distributed database: These are databases of work team, local offices and factories and other work places. Distributed databases may involve sectors of operational databases and user databases. ("Database."1)
IV) Some examples of Database:
Online Database :
-SABI
-Who´s who
-GreenFILE EBSCO
V) See also
- What is a Database?
-A primer on database and catalogs VI References
Brenner Eric. "What is a Database?" Skyline College,. 10/19/04 2004.Web. LSCI 106 Online Research. 11/09/09 <http://www.smccd.net/accounts/brenner/lsci106/whadbase.html>.
Burtle Laura, et al. "A Primer on Databases and Catalogs." University System of Georgia.Web. aula global. 11/09 <http://www.usg.edu/galileo/skills/unit04/primer04_02.phtml>.
"Database." wikipedia. 18/12/09 2009.Web. wikipedia. 17/12/09 <http://en.wikipedia.org/wiki/Database#Types>.
Created 20.12.09
Copyright 2009, Group 70 D
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