The Database Migration Service of Amazon Web Service

Amazon Web Service Database Migration Service (AWS DMS) is an optimized cloud-based platform used primarily to migrate databases from on-premises systems to the cloud or from one cloud provider to another. With AWS DMS, you can choose either one-time migration of databases or have continual replication of changes to data made at the source database to the target database. However, for this to happen, both the source and the target databases must be continually in sync.

AWS DMS migrates databases between relational databases, NoSQL databases, and data warehouses. It functions only when the source and the target databases are linked so that it can know from where to extract the data and where to load it to. The next step for database migration is to specify the activity that will replicate the data from the source to the target.

What makes AWS DMS stand out is that it fully automates the migration process and no human intervention is required at any stage. This is applicable even when the keys and the tables required for migration are absent in the target database. In this case, the AWS SCT (AWS Schema Conversion Tool) has to be used for creating tables, views, indexes, and triggers in the target database. Since AWS DMS is based in the cloud, all its benefits like cost-efficiency, flexibility, improved performance, and high security are available to users.

Organizations can opt for any one of the two types of database migration with AWS DMS, depending on several variables of the databases.

Homogeneous Database Migration

The pre-condition of this type of migration is that the engines of the source and the target databases, the data types, codes, and schema structuresbe the same. It is a simple process. Once a link is established between the source and the target, the full database is migrated in one shot. Examples of homogeneous migration are Oracle to Amazon RDS for Oracle, MySQL to Amazon RDS for MySQL, MySQL to Amazon Aurora, and Microsoft SQL Server to Amazon RDS for SQL Server. While carrying out this process, ensure that the source database operates on the Amazon EC2 instance or an Amazon RDS database.

Heterogeneous Database Migration

Heterogeneous database migration with AWS DMS is done when the database engines, data codes and types, and the schema structures of the source and the target databases are different. The migration is in two stages. First, the AWS SCT is used to format the data structure of the source database so that it matches that of the target database. Once this stage is completed, the actual migration is carried out. The source database for Heterogeneous Migration must be either on an EC2 instance or an Amazon RDS database.Examples of heterogeneous migration are Oracle to PostgreSQL, Microsoft SQL Server to MySQL, and Oracle to Amazon Aurora.

Select the method that best suits your organization.