I like Oracle database. It is efficient, easy to use for beginners and professionals – its tools for query analysis and optimization are masterpieces. But it has a very annoying “feature” – empty text (containing 0 characters) is stored in the database as null. Where did such a feature come from? Probably from the ancient ages, just after the dawn of time, i.e., the late 70's . In that age, memory (RAM and disks) was very limited and system designers did their best to use as little memory as possible.
You may not believe it but the items in this picture are not just kids’ toys; they are important parts of the software development process! We call them “database tokens.” When there are multiple developers on the project and you are not creating a few java classes for yourself, you need a versioning system which stores files with the source code. We use GIT, which allows developers to work simultaneously on the same module or even on the same Java file.
A real-life example: Let’s assume that we have a system which stores data for distributors who sell products manufactured by some company. Each distributor receives points for selling products and may redeem a specified number of points to obtain a discount or extra bonus. Points are calculated by an external system and updated very frequently – after processing of each order placed by the distributor himself, a member of the distributor group, or a customer assigned to the distributor.