AWS DATABASE MIGRATIONS

The AWS Database Migration Service allows you to migrate data from a source database to a target database. During a migration, the service monitors changes being made to the source database so that those changes can be applied to the target database and keep the two databases synchronized.

The source and target databases can be of any engine type.

The 2 types of database migrations are:

1. Homogenous migrations - where the source and target database engine types are the same.

2. Heterogeneous migrations where the source and target database have different engine types.

In homogeneous database migrations, the source and target database engines are the same or are compatible :

1.) Oracle to Amazon RDS for Oracle.

2.) MySQL to Amazon Aurora.

3.) MySQL to Amazon RDS for MySQL.

4.) Microsoft SQL Server to Amazon RDS for SQL Server.

Since the schema structure, data types, and database code are compatible between the source and target databases, this kind of migration is a one step process. You create a migration task with connections to the source and target databases, then start the migration with the click of a button. AWS Database Migration Service takes care of the rest. The source database can be located in your own premises outside of AWS, running on an Amazon EC2 instance, or it can be an Amazon RDS database. The target can be a database in Amazon EC2 or Amazon RDS.

Heterogeneous Database Migrations In heterogeneous database migrations the source and target databases engines are different, like in the case of Oracle to Amazon Aurora, Oracle to PostgreSQL, or Microsoft SQL Server to MySQL migrations. In this case, the schema structure, data types, and database code of source and target databases can be quite different, requiring a schema and code transformation before the data migration starts. That makes heterogeneous migrations a two step process. First use the AWS Schema Conversion Tool to convert the source schema and code to match that of the target database, and then use the AWS Database Migration Service to migrate data from the source database to the target database. All the required data type conversions will automatically be done by the AWS Database Migration Service during the migration. The source database can be located in your own premises outside of AWS, running on an Amazon EC2 instance, or it can be an Amazon RDS database. The target can be a database in Amazon EC2 or Amazon RDS.

You can use the AWS Schema Conversion Tool (AWS SCT) to convert your existing database schema from one database engine to another. You can convert relational OLTP schema, or data warehouse schema. Your converted schema is suitable for an Amazon Relational Database Service (Amazon RDS) MySQL DB instance, an Amazon Aurora DB cluster, an Amazon RDS PostgreSQL DB instance, or an Amazon Redshift cluster. The converted schema can also be used with a database on an Amazon EC2 instance or stored as data on an Amazon S3 bucket. AWS SCT supports several industry standards, including Federal Information Processing Standards (FIPS), for connections to an Amazon S3 bucket or another AWS resource. AWS SCT is also compliant with Federal Risk and Authorization Management Program (FedRAMP)