Caching strategies

Remember the answer so you do not have to ask again. Then figure out when the answer goes stale.

Definition

Keeping a copy of an expensive-to-fetch result in a faster, closer store so future reads can skip the work, with rules for when to invalidate or refresh it.

Step 1

Predict first

In one or two sentences, what do you think this concept means? Wrong is fine; the small struggle is what makes the answer stick.