Am I missing something?
As I understand it, the store acts like a cache, keeping a reference to every model that was loaded.
Isn’t it kind of a memory leak?
Should I clear it by myself? What are the best practices?
Yes, the store caches all records it’s seen by default. You an unload them with the unloadRecord, unloadAll methods if you like. It depends how much data you are dealing with if it is actually a problem or not