A cache keeps a few recently useful answers close, so most requests skip the slow trip to a database or disk. When it is full, the eviction policy decides what goes: LRU drops the entry used longest ago, LFU the one used least often.
A cache keeps a few recently useful answers close, so most requests skip the slow trip to a database or disk. When it is full, the eviction policy decides what goes: LRU drops the entry used longest ago, LFU the one used least often.