I am moving on-premise SQL Server and database to Azure PaaS. I used the Azure Data migration tool from Microsoft and created the database and copied the data to the Azure environment. It worked fine.
Due to some concern prod go-live postponed. Now on the next go-live, I need to take only data by using migration tool. I have confusion that how it works second time when I do data migration.
Does it delete all the and add once again?
Does it add only data which is not present yet in Azure database, compared to the on-premise data?
Please help me.
Data Migration Assistant (DMA) is able to migrate the data only (without the schema) if the same schema exists on the destination Azure SQL Database. You just need to specify that on the migration scope.
However, DMA expects the database tables on the destination to be empty or it will return an error specifying that for each table that is not empty. DMA will not empty the destination tables for you, if they are not empty, you will have to do it on your own. You can use Azure Data Factory or Azure SQL Data Sync instead of DMA to migrate the remaining of the data that was not migrated on the first migration attempt. But you can also consider performing a full migration with DMA on a brand-new Azure SQL Database instead of migrating the remaining of the data by first comparing what was migrated on the first migration attempt, because that comparison will for sure be very time-consuming process no matter what tool you use for the migration.