Application Architecture
الوحدة 6
CQRS
Separating the model you write through from the model you read through: a spectrum of four levels, what each one buys, and why the top of it is rarely justified.
32 min2 lessons
ابدأ الوحدةما ستصبح قادرًا عليه
- Separate CQRS from event sourcing and from having two databases.
- Place a system on the CQRS spectrum and justify moving one step.
- Explain the consistency consequences of a separate read store.
- Design a read model shaped by screens rather than by the write model.
- Recognise where CQRS adds cost without buying anything.
- 10 min
01CQRS Is a Spectrum, Not a Switch
At its simplest CQRS is two sets of types in one codebase. At its most elaborate it is two stores kept in sync asynchronously. Most of the value is available near the bottom.
- 11 min
02Read Models, Staleness, and the Cost of Level 4
Once the read store is updated asynchronously, you have accepted eventual consistency. That is a product decision before it is a technical one, and it needs designing rather than discovering.
CQRS
6 questions · pass at 75%