Open Source Options
If your site runs on open-source software, it’s likely to have one of two database applications available: MySQL or PostgreSQL.
MySQL (http://www.mysql.com/) is the most popular open-source database application, and most open-source web services, such as forums or blog software, work with it. MySQL powers many large sites but has limited ability to coordinate multiple database edits at the same time.
For a site that has a large, active community of contributors, MySQL might end up running into scaling problems. MySQL supporters will, of course, refute this, and new features are added all the time, so keep an open mind.
PostgreSQL is also often mentioned as a free database server option with stronger protections and tools for working on chunks of the database at one time. PostgreSQL also offers a less restrictive license for those who want to bundle a database application with software that they built.
Here’s an article that compares the two and a webpage where you can find an older version of MySQL’s own manual, which should give you some historical idea of the differences in the two servers.
Windows Databases
If you are using Microsoft Windows, there’s Microsoft Access part of the professional version of Microsoft Office. This can be a database container only – a file sitting on your web server storing the data. Many web hosts that run Microsoft’s .Net software, which uses pages that end in “.asp,” will be familiar with hosting Access databases. Because all the data is in a single file, it’s also easy to move or backup (or to corrupt — but that’s another story). You don’t technically need to have Access software to use an Access file as your site’s database. You just need someone with the software to create the file for you initially, and then the Windows software on your web server can handle the communications between the website and the underlying database.
Microsoft Access can also be a powerful way to edit directly the information stored in your site’s databases. To get to that data, Access requires you to describe all the information you want to edit or change in a file called a “form.” But once you’ve done that, Access offers the same useful features as Microsoft Word, including checking, cutting and pasting.
On the downside, Access only runs on Windows computers. And if you switch computers and want to edit your database with Access, you’ll have to set up that custom “form” all over again. In contrast, if you build HTML-based forms that run in a web browser and add, edit or display information from your database, you can manage your database from anywhere, on any computer with a web connection.
The next step up on the Windows side is Microsoft SQL Server, a database server that can handle a significant load and offers some snazzy development tools — but the cost starts at around $5,000.
Macintosh Databases
On Macintosh computers, you can run MySQL or PostgreSQL. But if you want a beginner-friendly graphical interface to create and edit databases, the latest version of FileMaker is fully relational and can handle significant loads. FileMaker has not been commonly used to create or serve website databases, but it’s worth a look now, especially if you’re a Mac-only operation.
Once you start looking at more powerful solutions, you’ll want to bring in some professional assistance.