# Read Replica

RDS read replicas is the most technique that be used to improve read performance. If we create read replica within same region , the charge is free.

To Know:

* we can replicate the DB across `AZ` and `Region` or within `AZ`.
* the read data from replica is eventual consistency.
* Applications must update the connection string to leverage read replica

#### Usecase

* You want to run a reporting application to run some analytics and product application taking on normal load on DB.

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