It can and is done. Place I last worked at built an in house data model and lookup engine on MS SQL Server to find relations between arbitrary data points on e

It can and is done. Place I last worked at built an in house data model and lookup engine on MS SQL Server to find relations between arbitrary data points on edges. I know that it is currently used live in production and handles real time fraud evaluation at a large scale (it's a private company and not a liberty to disclose actual payment volume). With proper indexing and careful design it is scalable, but as with everything, you need to dedicate time to performance analysis and design work.