Data migration can be a life time easy task, if you planned out correctly having rollback in place. Have detailed and meaningful discussions with business owners about new DB features and their use in new DB environment, get confirmation on agreed minimum downtime and most importantly how this migration is going to take place in a phased manner. E.g. Test/Staging or Pre Prod followed by production. In todays modern DB world, minimum downtime is achievable with features like log shipping, availability groups and replication in case of SQL server. Only challenge here is how much downtime is sustainable for the business and same needs to be discuss. All these factors to be considered when you are planning for DB migration.

To minimize downtime during an unexpected database migration, focus on preparation and execution. Start by creating a backup to safeguard data. Use tools like replication or incremental migration to move data without disrupting the current system. Plan the migration during low-traffic periods to reduce impact. Test the process in a staging environment to catch issues early. Finally, have a rollback plan ready in case things go wrong. Clear communication with stakeholders ensures everyone stays informed throughout the process.