Cache invalidation really is one of the hardest problems in computer science
Cache invalidation really sounds to me like a math problem. Instead of a Processor, let&#x27;s say it is a jewel store with limited display space at the front of the store and a lot of inventory  in the back, instead of cache misses you have window shoppers and walk-ins that won&#x27;t engage with sales staff or have limited time so you have lost sales&#x2F;customer and a catch hit is the opposite of that. At what point so you invalidate a jewel displayed at the front to rotate it with an inventory item? Let&#x27;s also assume customers buy multiple jewels if the same type and will not buy in less quantities than they desire or wait for staff to get more at the back because you have a competing store across the street.<p>Is that about right the way I described the problem? If so, this really might be a math problem like the travelling sales man, not exclusive to compsci.