Issue link: https://resources.awscloud.com/i/1496544
you might need to run to overcome these issues and successfully complete the database migration. Data Movement Cloud providers are highly alert to the requirements their potential clients have about moving their on-premises databases to the cloud with minimal cost and disruption. Each vendor offers tools to expe‐ dite the move. AWS, for instance, offers numerous papers laying out in detail how to migrate from various on-premises databases to AWS, including procedures for Oracle, MySQL, and PostgreSQL. Even so, migrations to the cloud can involve disruptive and costly downtimes. A migration tool, whether provided by the cloud vendor or by a third-party provider, must be able to handle all aspects of the database, such as schemas, user permissions, triggers, and stored procedures. We recommend that you keep a journal during your early migra‐ tions, because the lessons you learn along the way will inform you and your colleagues as you pursue further migrations. Should enough bad things happen that you decide to use another vendor— or not to migrate at all—the journal will provide important evidence to support that decision. Migrating the Database Many cloud providers and third parties offer migration services, such as Microsoft Azure Database Migration Service and AWS Data‐ base Migration Service, that are well worth consideration. These are advertised as being fast, smooth, and easy. However, you might pre‐ fer to use existing processes with which you are familiar, such as restoring from a backup to a new database environment, and using replication. If you use a database migration service, you can keep your source databases fully operational during the migration to the cloud and minimize the downtime for applications that rely on the database. This facilitates the key goal of minimal downtime, cited by many organizations migrating to the cloud. Figure 3-1 illustrates how AWS Database Migration Service creates the tables, loads data, and keeps the tables synchronized with the source database tables. 32 | Chapter 3: Moving Your Databases to the Cloud