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Comment by christiansakai | Hacker News Reader

Please enlighten me about why Redis is a good use case here.

Won't Redis cache eviction policy make it not a good use case to be a general purpose database, compared to, MongoDB?

I added a few more notes on when/why to use Redis and when to use something else: https://github.com/fpereiro/backendlore#redis . Redis can take you surprisingly far as a general purpose database. I prefer to use either Redis or a relational database, but I'm in no position to tell you that you should do that too, particularly if MongoDB works well for you.

Could you elaborate on why your first choice would be Redis? I tend to go for Postgres, but mostly out of habit and familiarity.

I love working with fundamental data structures (sets, lists, hashes) much more than working with relational databases. I feel I'm more productive and my code is shorter. It does, however, require far stricter validations in the code; in general a lot of what a relational database does for you (in terms of type validation, schemas and even data consistency), you must do yourself in code or by using redis carefully.

Redis has plenty of configuration, IIRC the cache eviction policy isn't the default configuration. By default it also writes to disk periodically to recover in case of crashes.

Isn't it said in the article that Redis can be replaced by anything else

> _redis can be replaced or complemented by another NoSQL database (such as MongoDB) or a relational database (such as Postgres). Throughout this section, where you see redis, feel free to replace it with the database you might want to use._

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