Does RDS for MySQL Support Multiple Accounts?
Yes, RDS for MySQL supports multiple accounts. Users can assign different rights to these accounts through authorization commands to control access to different tables. Each table is independent of each other.
Performance is not affected when multiple accounts access tables. Concurrent access of multiple sessions increases system resource overhead. For details, see the number of connections in MySQL 5.7 Test Data.
For more details about MySQL permissions, see official MySQL documents.