Very interesting, thanks for the answer! For the application and data structure I have in mind, I expect to need lots of range iteration over small values (<32 bytes?) and relatively infrequent writes, so Badger might not be a good fit. At a minimum sounds like I'd need to set up my own benchmarks.
For our system database[0] I am using BoltDB. It is a search engine with the database updated nearly in batch, so write performance is a non issue. The Go/BoltDB custom index has been running without any issues under moderate load for 2 years and the performance is great (a molecule information page can be delivered in less than 50ms to the end user at 99.9% percentile).
So, you should really test your read/write ratio with the size of the keys and payloads before selecting one solution or another. Even on the Badger tests, you can see that it can vary a lot.
