pg_upgrade in link mode typically takes less than a minute to run unless you have a lot of tables; the runtime is dependant on the number of database objects, n

pg_upgrade in link mode typically takes less than a minute to run unless you have a lot of tables; the runtime is dependant on the number of database objects, not rows or size of the database. Database statistics are not preserved across pg_upgrade so you'll have to run ANALYZE on the database after the upgrade which may take a while as it usually needs to read all or almost all of your data. I just recently upgraded a ~1 TB database, the actual upgrade process took less than a minute but analyzing it took much longer.