sourceDbInstanceIdentifier

The identifier of the DB instance that will act as the source for the read replica. Each DB instance can have up to 15 read replicas, except for the following engines:

• Db2 - Can have up to three replicas.

• Oracle - Can have up to five read replicas.

• SQL Server - Can have up to five read replicas.

Constraints:

• Must be the identifier of an existing Db2, MariaDB, MySQL, Oracle, PostgreSQL, or SQL Server DB instance.

• Can't be specified if the SourceDBClusterIdentifier parameter is also specified.

• For the limitations of Oracle read replicas, see Version and licensing considerations for RDS for Oracle replicas in the Amazon RDS User Guide.

• For the limitations of SQL Server read replicas, see Read replica limitations with SQL Server in the Amazon RDS User Guide.

• The specified DB instance must have automatic backups enabled, that is, its backup retention period must be greater than 0.

• If the source DB instance is in the same Amazon Web Services Region as the read replica, specify a valid DB instance identifier.

• If the source DB instance is in a different Amazon Web Services Region from the read replica, specify a valid DB instance ARN. For more information, see Constructing an ARN for Amazon RDS in the Amazon RDS User Guide. This doesn't apply to SQL Server or RDS Custom, which don't support cross-Region replicas.