There's no need to migrate the database, that shouldn't be an issue at this size. Caching should be implemented as another comment suggested.

I'd be interested as well.

The basic idea is to keep data as close to the processor as possible, so with a database that means storing the result of commonly used queries in memory.

• https://aws.amazon.com/caching/
• https://aws.amazon.com/caching/database-caching/

I have no idea, just inferred that from some other posts.