A company is running a batch analysis every hour on their main transactional DB, running on an RDS MySQL instance, to populate their central Data Warehouse runn...

A company is running a batch analysis every hour on their main transactional DB, running on an RDS MySQL instance, to populate their central Data Warehouse running on Redshift. During the execution of the batch, their transactional applications are very slow. When the batch completes they need to update the top management dashboard with the new data. The dashboard is produced by another system running on-premises that is currently started when a manually-sent email notifies that an update is required. The on-premises system cannot be modified because is managed by another team.
How would you optimize this scenario to solve performance issues and automate the process as much as possible?