In order to argue that redis isn't a database you have to first define what a database is and explain why redis doesn't fit that definition. All the author did

In order to argue that redis isn't a database you have to first define what a database is and explain why redis doesn't fit that definition. All the author did was assert that redis isn't a database and give 3 use cases. This is just bad writing, to be blunt. And for what it's worth antirez wrote an HN clone using redis as the database.