Comment by dathinab

Honestly whatever kind of DB you are speaking about always be wary of "niche/side features" which don't fit it's core design goals, they tend to have unexpected limitations.

listen/notify isn't necessary a replacement for redis or other pub/sub systems, redis pub/sub and similar isn't necessary a replacement for idk. Kafka or similar queue/messaging system

but a lot of companies have (for modern standards) surprisingly small amounts of data, very even a increase by 2,3,4x still isn't that big. In that case listen/notify and similar might just work fine :shrug:

also same is true the other way around, depending on you application you can go redis only, as long as you data volume stays small enough and needs for transactional/sync are reasonable simple enough (with watch+exec, NX,XX options etc. and maybe some redis side lua scripts you can do quite a lot for data synchronization). Issue with that is that stylistically redis data sync/transaction code is often much more similar to writing atomic data-structures then to SQL transactions, and even for SQL transactions there is a trend of devs severely overestimating what they provide, so often you are better of not touching on it when you can avoid it, also BTW. redis has something very similar to sqlite or Notify where "basically" (oversimplified by a lot) there is only one set of writes done at a time ;) (and then afterwards distributed to replicas), just that outside of some micro lua scripts you don't really run much logic outside of some NX, XX checks etc. so it's not blocking much and it's "more or less" all just in memory not touching a WAL (again oversimplified).