Question

Chapter 1 introduces some basic features on data and database, what your thoughts are on them? Usually, there are many tools or software to store your data, can you tell the difference between them and the database management system?

Answer 1

The features of a database include holding data (of course) in tables. In the “old days” we didn’t have relational databases which only means that a single table would be use to hold all the information for any given record. With relational databases we have one table that holds some data and another (or more) to hold related data. An example would be one table that holds a persons name, another table would hold his address. Why have another table for that? What if the person has several address because he’s rich and can afford a home in NY and one in CA and another if FL. in a “Flat file” db we’d have to create three records just for this one person. If the same person has more than one email address and more than one phone etc… You get the idea.

Now, another thing a modern day db has, is a way to access that data. We call that a Structured Query Language or SQL. Where is this important? If we consider the old DB’s we could look at an excel spreadsheet or a simple comma separated text file they would qualify as a database. In the most basic of definitions they qualify. However, they don’t have a way of accessing the data. They are like tables in a DB with nothing else to support them they are just text.

Some of the most well-known database software programs include:

• ADABAS
• IBM DB2
• Microsoft Access
• Microsoft Excel
• Microsoft SQL Server
• MySQL
• Oracle RDBMS
• QuickBase
• SAP Sybase ASE
• Teradata