Section checkpoint

Data Layer

10 questions drawn from the 5 chapters in this section. If most land on the first try, you are ready for the next section. If not, the explanation after each answer says which idea to revisit.

Checkpoint

10 questions · first-try answers earn the most XP

1. Product items have wildly different attributes, and you mostly fetch whole items. Which family fits?

2. When does the chapter say to reach past a single relational database?

3. A page renders 500 products by querying the database once per product (501 queries, 8 seconds). What is the real problem?

4. Why are database indexes described as trading write cost for read speed?

5. What does consistent hashing help with in a sharded database?

6. Why is a single global counter a bottleneck when generating IDs from a database?

7. Where does consistent hashing most commonly show up in real systems?

8. Removing a server from a consistent hashing ring causes what data movement?

9. Why does stemming matter for a search engine, and what does it fix?

10. Why does the chapter advise starting with your database's built-in full-text search?

What this checkpoint covers

Put it to work in a drill

Next section: Caching and Delivery