It was glogin.sql
Daniel, July 09, 2018 - 5:39 pm UTC
Hello Connor,
Thank you for this suggestion. I knew about login.sql, I am using it since I saw Tom's post about using login.sql in order to display customized sqlplus prompt. The alter session wasn't in login.sql and I was unaware of glogin.sql. The alter session was in glogin.sql - now the mystery is solved :). Thank you for your time.
Daniel
July 12, 2018 - 9:41 am UTC
glad we could help