Which DBMS to choose?

Question

PostgreSQL

The data model is a set of HASHMAP - key-value fields. Redis, for example, is great for storing them, except for the situation when you need to do a search - a selection of data according to criteria. With less performance, but it does the job - Mongodb is suitable. As a result, they now live in a pair - Redis is constantly working with data and Mongodb is constantly synchronizing. This scheme works, but is inconvenient and leads to errors. If you leave only Mongodb, then the performance drops dramatically (wiredTiger is much better, but still not the same). If in more detail about the stored data, then in fact this is user data, where each user is a key-value set. Some fields require an index.
Those. need the speed of Redis with the ability to quickly search by fields inside a HASHMAP

Answer 1

https://www.youtube.com/watch?v=aVyFEOZy9Y4