I'm in the middle of upgrading NAV from 4.8 to 5.0.5 and running 'navsyncdb' to alter the database schemas.
(The database is named nynav because this is a test upgrade)
/#navsyncdb Existing namespaces in nynav search path: "$user", public. Adding manage, profiles, logger, arnold, radius. Applying outstanding schema changes sql/changes/sc.04.09.0001.sql: OK sql/changes/sc.04.09.0050.sql: OK sql/changes/sc.04.09.0100.sql: OK sql/changes/sc.04.09.0110.sql: OK sql/changes/sc.04.09.0200.sql: OK sql/changes/sc.05.00.0001.sql: OK sql/changes/sc.05.00.0010.sql: operator is not unique: unknown || integer LINE 29: 'SNMP v' || snmp_version || ' read profile #' || row AS na... ^ HINT: Could not choose a best candidate operator. You might need to add explicit type casts.
Server version Postgresql 9.6.17
Since this is a newly created database with imported data it might be missing some environment variables or something.
--Ingeborg