Migrating to DynamoDB from RDBMS

In the previous section, some of the key features of DynamoDB were discussed, as well as some of the key differences between DynamoDB and a traditional RDBMS. In this section, a strategy for migrating from an RDBMS to DynamoDB that takes into account these key features and differences is proposed. Because database migrations tend to be complex and risky, we advocate taking a phased, iterative approach. As is the case with the adoption of any new technology, it’s also good to focus on the easiest use cases first. It’s also important to remember, as we propose in this section, that migration to DynamoDB doesn’t need to be an all or nothing process. For certain migrations, it may be feasible to run the workload on both DynamoDB and the RDBMS in parallel, and switch over to DynamoDB only when it’s clear that the migration has succeeded and the application is working properly.

The following state diagram expresses the proposed migration strategy:

Migration phases

It is important to note that this process is iterative. The outcome of certain states can result in a return to a previous state. Oversights in the data analysis and data-modeling phase may not become apparent until the testing phase. In most cases, it will be necessary to iterate over these phases multiple times before reaching the final data migration state. Each phase is discussed in detail in the following sections.