How to Address Dynamics 365 Online v9 Upgrade Performance Challenges
https://www.linkedin.com/pulse/how-address-dynamics-365-online-v9-upgrade-challenges-stephan-smith/
https://www.crmviking.com/2019/02/disaster-recovery-for-dynamics-365.html
https://docs.microsoft.com/en-us/business-applications-release-notes/april19/