[masukomi]

in my XP materialized views are just another layer of caching, and caching consistence is, of course, one of the bigger problems in computing.

It's a great tool, but also one that can easily become a source of its own problems. One big issue is that devs stop caring because "the materialized view is fast" and you end up with materialized views that take 20 minutes to generate, and thus are 20 mins out of date the moment they come online. I'm not being hyperbolic.

DB Normalization is good, but sometimes it brings its own problems. Sometimes duplication is "better". Sometimes you should ask yourself "is a document db like MongoDB a better solution for our needs?"