Why do so many programs use rational databases instead of loading the data during startup and keeping it in memory? Especially for smaller datasets I would think, that a database adds unnecessary complexity and overhead. Also, a lot of data can be saved using modern RAM and when using an in-memory approach, optimized data structures can be utilised to further improve the performance
Good luck keeping an entire corporate database in RAM only. It’s not a 1:1 ratio of space on disk to space on RAM, pointers to the appropriate addresses also have to be stored in memory.
Even for a relatively small database, say, 100MB, keeping it in RAM only is a safety hazard. Even if you fully isolate the memory, make it completely “impregnable” from any outside application, memory corruption remains a problem. If you don’t isolate, memory leaking into or out of the database is also a problem, the former being much more damaging.
The fact that you still have to dump it into a hard drive also shows the main problem of keeping it in RAM: if the database service goes down, you “lose” the entire database
Put it another way, your suggestion is to have Notepad open, reading/writing the data and only saving at certain intervals.