#cache-identity

What keyFields value does Apollo Client v3 InMemoryCache use for objects without id or _id?

I am configuring Apollo Client v3 InMemoryCache and need to know how cache identity is assigned when a normalized object has neither an id nor an _id field. The documented fallback chain suggests id first, then _id, then storage under the parent path only, but it is unclear whether a custom keyFields policy returning an empty array changes that fallback or p