Comment by vladich

Sure, but that's not the main issue. If you add a global cache, it will have only a marginal value. There are Postgres extensions / forks with global cache and they are not wildly more efficient. The main issue you still do not understand is for different parameters you _need_ different plans, and caching doesn't help with that. It can help with parsing, sure. Parsing is very fast though, in relation to planning. And you keep conflating "prapared" statements with plan caching. Ok.