Databases

Possible topics:
- SQL vs NoSQL
- Traditional SQL performance: Latching, Locking. Recovery and Data pool, see Stonebraker  https://www.usenix.org/legacy/events/lisa11/tech/slides/stonebraker.pdf 
- ACID
- Normalisation
- b-trees
- indexes
- In-memory
- SSDs vs HDD
- ORMs
- different DBs: redis, mongodb, postgresql
