1. Read-Your-Writes Consistency

After you write something, you will always see your own update on subsequent reads — even if replicas lag.

Example:

1. Update user table: 
    UPDATE user SET name = "Bakhrom" WHERE id = 123
2. Read that data:
    SELECT name FROM user WHERE id = 123
3. You will see name = "Bakhrom", not the old version

Methods:

Session / Sticky Routing

• After a client writes, all its future reads go to the same replica.
• That replica is known to have the client’s latest write.

Used by:

• Redis Cluster
• Cassandra (“stickiness” via driver)
• Web apps with session affinity

Client-side version tracking

• The client stores the version (timestamp, vector clock, session token) of its write.
• Reads include this version → servers must return at least that version.

Used by: