This question is about the Substrate host functions and storage implementation and is not specific to FRAME (although relevant FRAME-related information is welcome).
Imagine that the runtime knows it will need to read a bunch of keys. Perhaps those keys are even located nearby in the storage trie under a common prefix. Is there any way the runtime can request a bulk read of many keys and get a performance benefit as opposed to reading them one-by-one?
If I read them one-by-one, each read would individually have a cache miss and db access.