Data infrastructure in the real world, for non-trivial systems, moves slowly. Migrations are costly and risky. If you need to optimize query performance, you are likely working on one of those non-trivial systems. We have some MongoDB clusters at work (one in my team). Would we have picked it today? Maybe not, because the mindshare isn't there. Does it work fine right now though? Yes, definitely, we have no issues really (the suck in that system is elsewhere).
Here is my recipe for even faster query performance:
1: export the data out of MongoDB
2: import the data in PostgreSQL, ClickHouse, DuckDB, whatever
3: create the indexes there
4: uninstall MongoDB
But then they wouldn’t be able to sell their dashboard view. That’s the point of the tutorial/salespitch/s.
Does anyone even use MongoDB anymore? Is this article from 2019?
Data infrastructure in the real world, for non-trivial systems, moves slowly. Migrations are costly and risky. If you need to optimize query performance, you are likely working on one of those non-trivial systems. We have some MongoDB clusters at work (one in my team). Would we have picked it today? Maybe not, because the mindshare isn't there. Does it work fine right now though? Yes, definitely, we have no issues really (the suck in that system is elsewhere).