Introduction to Databases for the Web: Pt. 1 - Page 2

Types of Databases

These days, when you talk about databases in the wild, you are primarily talking about two types: analytical databases and operational databases.

Let's examine each type.

Analytic Databases

Analytic databases (a.k.a. OLAP- On Line Analytical Processing) are primarily static, read-only databases which store archived, historical data used for analysis. For example, a company might store sales records over the last ten years in an analytic database and use that database to analyze marketing strategies in relationship to demographics.

On the web, you will often see analytic databases in the form of inventory catalogs such as the one shown previously from Amazon.com. An inventory catalog analytical database usually holds descriptive information about all available products in the inventory.

Web pages are generated dynamically by querying the list of available products in the inventory against some search parameters. The dynamically-generated page will display the information about each item (such as title, author, ISBN) which is stored in the database.

Operational Databases

Operational databases (a.k.a. OLTP On Line Transaction Processing), on the other hand, are used to manage more dynamic bits of data. These types of databases allow you to do more than simply view archived data. Operational databases allow you to modify that data (add, change or delete data).

These types of databases are usually used to track real-time information. For example, a company might have an operational database used to track warehouse/stock quantities. As customers order products from an online web store, an operational database can be used to keep track of how many items have been sold and when the company will need to reorder stock.