Replication in SQL Server

Replication
- process of distributing data from one database to another on the same server or servers connected through LAN or the internet.
- synchronize data between databases that may be at remote location.
- maintain copies of database at more than one locations.
- It can be used for load balancing of server by maintaining area specific data independently and replicate later to have single version of data

Types of Replication

1. Snapshot Replication
2. Merge Replication
3. Transactional Replication

Snapshot Replication
- Snapshot of entire data is copied from publisher to the subscriber's database on regular
interval.
- This kind of replication is used for replicating data that doesn’t change frequently.
- It is used where the source can manage with out of date data.
- This replication is considered when amount of data to be replicated is small.

Merge Replication
- This allows both publisher and subscriber to work independently, online or offline and merges
the changes later.
- Here changes are track on both publisher and subscriber and then merged.

Transactional Replication
- This kind is used when changes are frequent.
- The replication agent monitors the changes at the publisher and distributes the changes to the
subscribers.
- Its required where up to date data is required.