Entity attribute value anti pattern - this has been well known for at least 20 years. It can be tempting when you want to design a "flexible" system but really needs to be used sparingly. I was BI team lead on a product where the architect insisted that it be used on every entity (>300) as you never knew when you might want to add some bit of data. It led to some interesting (multi-page) sqls and the project ultimately failed. This was one of the reasons. Slow performance and often runtime errors when expected data wasn't present and the application layer couldn't cope. It was a good learning experience. https://mikesmithers.wordpress.com/2013/12/22/the-anti-patte...