I´m migrating from RT 4.0.10 on Postgre 9.X. To RT 5.0.1 ons Postgre 12.X.
Done the # make upgrade-database. Without incidents.
I run fthe Full index (i have some warnings Words longer than 2047 characters are ignored. i think that there are for the attachments) with a new name for Table and Column. Add the text to the RT_SiteConfig.pm.
Im my case: