Yes, I agree. Most people I know would use RDBMS such as Postgres to store bulk of business data (customer accounts, transactions, receipts etc) and then use co

Yes, I agree. Most people I know would use RDBMS such as Postgres to store bulk of business data (customer accounts, transactions, receipts etc) and then use complementary systems for other purposes (so could be Memcache/Redis for caching, ElasticSearch for logs etc). It's not a false dichotomy of using either Postgres or Redis, you can use them alongside each other, they have different uses.