SELF-ASSESSMENT
Review Questions
1
What is atomic in a single document? How do “projection” and “$set” differ from “read-modify-write”?
2
How do "owned" fields differ from "price_paid" and a copy of the total current effect?
3
How can I ensure the array bounds, and where should I store the history after $slice?
4
When is a transaction necessary, even within a single collection? Why isn't a standalone setup suitable, and why doesn't a single node provide high availability?
5
How does `maxmemory 0` differ from the limit set with `noeviction`? What happens when an OOM occurs?
6
Why doesn't KEEPTTL return the expiration time? How does a key's TTL differ from the TTL of a field and from freshness?
7
How do you compare MongoDB to jsonb, and Redis to an SQL index? What happens when the scores are tied?
8
What should you do if the system is unavailable or if the cache, derived data, and state are lost?
Question 8 — Start of the lab. Sample answers — in the lecture notes, Section 16. Commands for running the lab on your own — Appendices P1–P17.