What does this mean to you?
If you are only working with 2020 Survey Databases, you'll see little change: The survey database file extensions will be different, .SQLite instead of .sdfx.
If you need to open previous versions of Survey Database, the files must be migrated to the new format.
Close Civil 3D and then install the Autodesk Civil 3D Survey Database Migration Utility, available online: Autodesk Civil 3D Survey Database Migration Utility.
Using Civil 3D 2020, any older version Survey Databases will be displayed with a warning symbol.
Right click the database and run the Migrate... tool.
Specify the input and output directories. If you want the new .SQLite file to be in the same folder as the old .sdfx file, then leave them the same.
Press Start, let it run, then click the X to close the dialog. Refresh the Survey Database to remove the warning symbol.