[yjh0502]

Could the algorithm be applied to block cache problem with single item size, like filesystem block cache or database cache?

[smaddox]

I was wondering the same thing. I suspect its value would decrease in those cases, due to the lower-level representation providing less semantic association, and therefore less information (per unit object) for modeling hit rate and lifetime. Also, the higher objects count would require more resources.

Edit: perhaps in a file system, the higher-level information could still be provided?

[jandrewrogers]

Even within database caches, while the page size is often fixed you are still caching and operating on more abstract multi-page objects of variable size. In a good cache replacement algorithm there is some implicit awareness of the relative sizes of these objects to optimize the replacement policy.