NOTE: This is the second post in our Windward learning series on the introduction to digital data. Missed the first one? Read it here.
SQL databases are the standard for persistent data storage. When someone is talking about databases, they are most likely talking about an SQL database. These databases are built on tried and true theories and are widely deployed around the world.
In general, data is stored in a row-based format. Each row is an object and contains information about each object. Objects can be related to each other, creating a more complex structure.
Three Major Examples of SQL Databases
Microsoft SQL Server
Microsoft SQL Server is the default SQL database for the Windows operating system. It works well out of the box on Windows machines. It has many provided features for .NET and Windows development, making it easy to get up and running for those platforms.
There is an Express version that is free, with restrictions. The full version costs money but is much more flexible and powerful.
Oracle SQL Database
The Oracle database is a major player as well. It scales extremely well to your needs and fits in smoothly if you are already using other Oracle products. Oracle databases can be very difficult to tweak and maintain, requiring IT with expertise and experience. However, it can yield incredible performance as well.
MySQL is an open source SQL database most commonly used in web servers. Since the Community version is free and runs on all major operating systems, MySQL is often a good place to start. It works best for small- to medium-sized projects but can work well in large applications as well.
Pros of SQL Databases
SQL databases and their management systems have many powerful built-in features:
- Scalability and redundancy. SQL databases are designed to work well with small applications running on a smart phone as well as massive server farms.
- Security. Security models allow certain users access to specific pieces of data.
- Support for multiple users. SQL databases are designed for multiple simultaneous users, both for reading and writing data.
Cons of SQL Databases
While SQL databases work well in many cases, they have negatives as well:
- IT resource requirements. IT resources are needed to set up and maintain the database; this includes both time and hardware.
- Learning curve. SQL databases all have their own specific software to learn.
- Language. You must learn Structured Query Language (SQL) to work with SQL databases.
When to Use an SQL Database
- Structured data. Your data is highly structured and that structure very rarely changes.
- Multiple users. The data needs to be manipulated often by multiple users and applications.
- Security. When you’re in need of a robust and flexible security system for your data.
When Not to Use an SQL Database
- Temporary Storage. If you have smaller and simpler local applications with simple temporary storage, usually file-based data will be better.
- External sharing. Sharing information with people and applications outside of your organization.
- Changing data structure. The data is diverse and the structure constantly changes.
The 15-Second Summary
SQL-based data sources are the most commonly used and proven data storage technology for software applications. The combination of robust features, data management tools, and multi-user compatibility make it the best choice for a wide variety of digital applications.
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Author: En-jay Hsu
En-jay is a software developer from Boulder, Colorado.
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