Benefits and Types of Database Migration Service of AWS
The Database Migration Service (DMS) is a cloud-based service of AWS. Users can migrate data either from an on-premises database to the cloud or from one cloud provider to another.
The DMS platform of AWS data migration service facilitates migration from NoSQL databases, relational databases, data warehouses, or any other data sources. It also helps in one-time data migration between databases or when the source and the target database are in sync, continual data replication between the two.
Benefits of AWS data migration service.
• No downtime: During the movement of databases through AWS data migration service, the source database remains fully functional and hence data migration to the target database can be carried on without downtime.
- User-friendly: AWS data migration service provides simple migration solutions. Additional drivers and applications are not required to be installed as it is fully managed by AWS DMS. After setting all parameters, migration is started directly from the AWS Management Console.
• Cost-effective: AWS data migration service charges users only for the volume of computing and storage resources used for migration. There are no flat charges or one-time upfront fees.
• Wide support base: Most widely-used and common applications are handled by AWS data migration service, leading to seamless migration between SQL, NoSQL, and text-based target databases.
• Dependable: AWS data migration service continually monitors the source and the target databases. In an outage, the migration is resumed as soon as the issue is resolved.
Types of database migration to AWS
There are two types of AWS data migration service.
• Homogeneous database migration: Migration is applicable here when the databases engines of the source and the target are similar. Migration is a simple one-step process as the data types, data codes, and the schema structures of the source and the target databases match each other. Examples include 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.
• Homogeneous database migration: Here, the AWS data migration service works when the engines of the source and the target databases are not the same and the data codes, data types, and schema structures are different. Hence, before migration schema structure and data code transformation have to be carried out. This is done automatically by the AWS data migration service. Examples are Oracle to Amazon Aurora, Oracle to PostgreSQL, or Microsoft SQL Server to MySQL migrations.
Despite the benefits of the AWS data migration service, there are limitations too. Users face issues with code and schema conversions as it is not handled directly by AWS DMS. instead, during heterogeneous migration, an AWS Schema Conversion Tool has to be used. Further, partial volumes of Data Definition Language (DDL) only are replicated by AWS DMS. Indexes, users, and privileges that are not directly related to table data cannot be processed by AWS Data Migration Service.
