Database Management Systems

This week’s discussion is on database management systems and in particular relational systems. The required reading was from Access Science and gave a general overview into DBMS. The basic components of a DBMS are hardware, software, data and users. The hardware is the actual computer that is used to store the information. In most situations there is one main computer that is called the server which stores and processes the data. Then there are client computers that can access the information from the server. These client computers can store certain pieces of information also. The software is the DBMS. There are two types of data within the DBMS. The first is the information needed by the company using the system and the other is the information about the database called the metadata. This information is generally refered to as the data dictionary or catalog. DBMS are built for unique users and designed for the user’s specific purpose.

The first additional article I looked at is called, Learn Oracle-What is Oracle?The required reading mentioned Oracle and I wanted to know a little more about it. Oracle is a relational database which stores data in tables and columns. The tables are the category of data while the columns give information about the category. For example, the table is the employee in a company and the column is information about that certain employee like their email address. There is a range of how complex a database is. Some are very simple and only store data while others are more complex. These multifaceted databases can include programming languages, facilities and utilities to support additional features. Oracle has the most advance feature set.

Most relational databases, like Oracle, access data through something called Structured Query Language or SQL for short. SQL allows you to manage your data by selecting it, inserting new data, updating old data and deleting data you no longer need. A system like Oracle is always running in the background of the operating system by maintaining data and finding out where it should be stored. There are a number of tools that Oracle uses to access the database and create new programs. These include, SQL Plus, Oracle Developer, HTML DB, and Oracle Enterprise Manager. One program that is supported by Oracle is Java, which is commonly used on the web.

The second additional article I looked at is called, MicrosoftAccess Database Fundamentals. Since the second assignment deals with Microsoft Access I thought this would be a great article to share with the class. Microsoft Access has a familiar look and feel to its family of Microsoft products that we use daily such as Word, Excel and PowerPoint. Access is like all other database systems and allows you to organize and manage data in an easy to use and flexible manner. The three major components to Access include tables, queries and forms. Tables are similar to spreadsheets like in Excel and are the building blocks to all databases. Like in Oracle, the table reflects a certain topic like employees and the columns of the table provide information about any given employee. These are called attributes in database language. A query is a way of recalling specific information from a given table or tables. For example, you have a table of products and the unit price of each product but you only want to see the products that are selling above the average price. You can instruct Access to only return these products instead of sorting through the whole table and picking out the products one by one. This information can easily be put into a report format so that it can be shared with prospective clients. Finally, this report can be posted to the web for all to see by exporting the report as an HTML file.