What Are the Different Types of Database Management Systems?
Database management systems allow users to store bits of information, organize it and retrieve some or all of it as needed. Each of the main types of database management systems requires a software program that creates records to organize the data and creates reports from that data. The software programs for databases create one of four common types: hierarchical databases, network databases, relational databases or object-oriented databases.
The hierarchical database is one of the oldest types of database management systems. It is most commonly used on mainframe computers. The database creator pre-defines the relationships between each record and its data. The structure requires a root record, or parent, from which the database designer creates a parent-child relationship for each bit of data that goes into the database.
A network database also organizes data by using defined parent-child relationships. Like a real family, the network database structure allows a piece of data classified as a child to have more than one parent. This is an improvement over hierarchical types of database management systems. It allows users to connect information in one database to another set of data through the parent record and the child record.
The relational database management system has increased in popularity because of its flexibility and ease of use. It allows the database designer to use individual pieces of information to create relationships between separate databases without the restriction of parent or owner relationships. The information in one database that ties it to data in a different one is a unique identifier, such as an employee identification number.
Relational databases management systems allow database designers to create one database to store payroll and salary information for employees. The designer creates a separate database for personal information such as home addresses and phone numbers. Different users might input and update the records in each database. Reports pull data from the records of any database in which the matching employee identification number is found.
Object-oriented types of database management systems provide a way to organize data other than numbers and text. Designers use them to accommodate multimedia items such as photos, music and videos. This database management system uses two identifiers for each item. The first is a descriptive object name, and the second is a miniature program with instructions or methods that the computer runs during storage and retrieval. The two parts become an object that the database users can organize like they can with text or numbers.
@nony - I agree, and think that one of the best ways to learn about databases is to take online tutorials. This is how I got my start – and I didn’t have to pay for the tutorials.
My library hosts online tutorials that patrons can access. I was able to connect to a database management system tutorial, complete with Flash video and audio, just on my library account alone.
It covered all the basics of Microsoft Access including how to build basic forms and reports, and a little preview of Visual Basic for the macro language.
If you’re wanting to get a start with database skills, the online tutorials are the best way to go in my opinion.
I think that if you’re an analyst, you should learn to use database management software – even if you don’t consider yourself a programmer.
I realize that most analysts are proficient in spreadsheet software but knowing databases is a definite plus. The reason is that analysts usually are required to use reporting tools.
While these reporting tools typically have a graphical interface to run the reports, they also have a Structured Query Language mode which lets you type in SQL statements directly into the database.
If you know how to do that, you can build some pretty powerful custom reports. You will definitely increase your value to your employer and set yourself apart from other analysts.
@NathanG - The article forgot to mention other types of database software like dBase and BerkelyDB, which are basically flat file databases.
Flat file databases are neither relational nor hierarchical in nature. They basically store records in a simple format of one record per row, kind of like what you would have in a text file.
I played with dBase back in the early days of database development, before Microsoft Access became king and dBase fell by the wayside. The only use of dBase nowadays is in Visual FoxPro, but of course that’s pretty much obsolete as well.
But flat file databases are where everyone should start first, in my opinion, before they move on to the concepts of relational databases.
I’ve used relational database software like Access and Oracle almost of my life. I wasn’t aware of the other kinds of systems, although I did have some fleeting exposure to object oriented database concepts.
Relational databases allow you to compartmentalize data into different data stores, not only within the same database but also across multiple databases.
In Access, for example, I sometimes bring in linked tables from Oracle or SQL Server, and I can build relationships and run queries on these tables just as if they were internal to the Access database.
This, to me, is the biggest advantage – flexibility. I can’t say the others don’t have that feature, I just haven’t used them like I said.
Post your comments