910 karma · joined January 27, 2015
Telling it from real experience.
[1] https://en.wikipedia.org/wiki/Object%E2%80%93relational_impe... [2] https://youtu.be/qI_g07C_Q5I?t=98
The goal of the Impedance impedance mismatch test is to identify such scenarios using a simple calculator and avoid them. In 2021, there are many single systems like Kafka, Redis, Cosmos, etc which can do multiple things way more efficiently. Many of these are OSS projects, so you wont get vendor lock-in.
You can certainly overlay cost to the calculator by adding an additional column. Cost should not be just the storage layer cost, it should include HR cost, licensing cost, overhead cost, basically TCO for each system in the data layer.
But I think generally by simply listing all your systems, you'll already kind of know how complex or simple your system is.
The car efficiency numbers came from Inside EVs as the article points out. I think they did a pretty thorough job. https://insideevs.com/features/392202/ice-vs-ev-inefficient-...
I think the blog talks about that in two sections. "First reason to use rollbacks: concurrency" and "Second reason to use rollbacks: leveraging index constraints" says why it's different in Redis.
Going back to the car analogy, if you are an electric vehicle, some things are completely obsolete when compared with gasoline vehicle.