Using the Database Migration Service of AWS

The Database Migration Service of the Amazon Web Service popularly called DMS AWS is based in the cloud and ensures seamless migration of data warehouses, NoSQL databases, relational databases, and any other type of data store. This migration is only possible when any one or both of the source or the target database operates in the cloud. Thus, it is easy to migrate databases from on-premises systems to the cloud or from one cloud provider to another.

Functions of the DMS AWS

DMS AWS facilitates either one-time migration or continuous migration of all changes made at the source database to the target provided both are kept in sync. However, when the source and the target database engines are different as in Heterogeneous Migration, the AWS Schema Conversion Tool (AWS SCT) has to be used to translate the database schema to the new platform. After this activity is completed, DMS AWS is used to migrate the database. All the benefits of the cloud such as security, speed to market, flexibility, and cost efficiencies can be had with this form of migration.

In a nutshell, AWS DMS is a component of the AWS Cloud and a server that runs the replication software. What is first needed is the establishment of a link between the source and the target so that AWS DMS will know from where the data has to be extracted and where it should be loaded. After this, a task has to be scheduled that runs on the data migrating server. AWS DMS automatically creates the required primary keys and the tables if they are not present in the target database. Otherwise, AWS SCT may be used for the creation of indexes, triggers, and target tables for migration.

Types of AWS Database Migration Service

Users can replicate data with high availability and combine multiple databases into petabyte-scale warehouses with DMS AWS. It is done by streaming data to Amazon Redshift or Amazon S3.

One of the two types of AWS DMS migration can be selected by the user.

Homogeneous database migration: This type of migration with DMS AWS is done when the database engines, data types, data codes, and schema structures of both the source and the target match each other. Migration here is a smooth and seamless process. Examples of Homogeneous Migration are Oracle to Amazon RDS for Oracle, MySQL to Amazon Aurora, MySQL to Amazon RDS for MySQL, or Microsoft SQL Server to Amazon RDS for SQL Server.

Heterogeneous database migration: Here, the database engines, data types, data codes, and schema structures of the source and the target databases are different. Hence, before migration, the schema structure and data codes have to be transformed. This is done automatically by AWS DMS. Examples are Oracle to Amazon Aurora, Oracle to PostgreSQL, or Microsoft SQL Server to MySQL migrations.

Organizations can choose one as per need.