1. Shared disk architecture:

    - Multiple Database server

    - Parallel processing on servers (Scalability)

    - If a server fails, client  re-routed to next available server in db cluster

    - servers are connected with Shared Storage infrastructure

2. Replication

    - Replica of server

    - Replicas are further distributed in different geography

    - Client task is distributed between replicas

    - Multiple replica in same location = high availability replica

    - If one replica fails, clients are re-routed to the next available replica

3. Partitioning and Sharding

    - Large data is divided into multiple logical partitions

    - Each partition contains subset of overall data

    - When partitions are placed in separate nodes in clusters = sharding

    - Each shard has computing resource to act as independent system

    - Allows clients to process data parallelly on partitions