Database Servers

A database server is a computer application which provides database services to other computers, this called client-server model. This term also described as a computer determines to run a program. Database management systems (DBMS) provides basic database server functionality and some DBMS’s (for example, MySQL) based on the client-server model to access database (Wikipedia 2006). There are many database servers provide by different vendors such as Microsoft SQL server, PostgreSQL, MySQL, Interbase and many more.

According to PC World (2006, p.1) there are several types of database:

1. Relational database
   A relational database stores all items needed in one database, sets them in some databases and making the relationship among them. For instance, a small-medium size enterprise (SME) wants to define the relationship between customers and orders in tables. Each customers and orders has their own unique ids so that two tables can be matched together. These databases named relational because they define these two connections (a customer form can be used to look up their order details form from the order table rather than storing double information). SQL is a common relational database which provides queries.
2. Object databases
   Object databases very carefully store data in self contained units (objects). These objects contain specific data, attributes and behaviors related to them. A simple example is a product database such as a shoes object, which has some attributes such as color, size and price. The main difference between relational databases and object is the method to access the data. To access the data objects from the object databases, usually programmers using object oriented programming language along with calling methods in their code. This may contain much information if it resided in the application code and sends the information to the object database. That’s why the application code is simplified. On the other hand, at the same time when the application and database are entwined together can cause complexity of accessing the data outside of the application.
3. Object-relational databases
   This kind of database combines both object and relational approaches. This gives the benefits of utilizing objects when it necessary to be tied to the strengths of utilizing relational databases.
4. Hierarchical databases
   The relational databases organize data in tabular form but hierarchical databases organize the data in a tree form. A parent node will lead their inherent child nodes (which these children may have their own further nodes). This type of database is similar with a Windows Explorer program which displays the contents of a hard disk or hard drive (double click the parent directory and then it will drop down the further information and so on). This provides multiple types of subsidiary data but also make it complicated to identify complex multiple types of single data items. Recent hierarchical databases have been common used in computer science fields than in real world applications and hierarchical systems are more popular with the existence of XML (Extensible Markup Language) that uses a hierarchical method as a general data exchange format.

References

Database Server 2006, last edited 4 November 2006, Wikipedia Foundation, Inc., n.a., viewed 1 March 2007, <http://en.wikipedia.org/wiki/Database_server>

Database Servers Buying Guide 2006, last edited n.a., Australian PC World, NSW, Australia, viewed 1 March 2007, <http://www.pcworld.idg.com.au/index.php/id;676007892> SQL

Database Server 2006, last edited n.a., Todd VerBeek, viewed 1 March 2007, <http://microsoft.toddverbeek.com/sql.html>