Level 2: Data · L2.4 Transactions & isolation
MVCC and snapshot isolation
Explain how versioned rows let readers and writers not block each other.
12 min · Pro
What you take away
- Every update writes a new version of the row tagged with the transaction that created it, instead of overwriting.
And 3 more inside the class, in Pro.
How the class is laid out
- The problem
- The simple version
- How a read picks its version
- Where it goes wrong in production
- Check your understanding