@Ashok Zubrewar​  coming to your 3 rd question, if you are using any external tables then non uc ADLS GEN 2 is mandatory, you can not use UC ADLS GEN2. as it hosts metadata and managed table data. there is no restriction in terms of your external buckets (ADLS GEN2 Storage regions should be on same region as UC ADLS GEN2 , but to avoid performance Issues best way is to have in same region). once you configure your non UC ADLS GEN2 and add storage credential and storage location, you should be good to access your ADLS GEN2 in UC, but currently we need to remember we have limitations in UC for external tables ( won't support OPTIMIZATION), databricks recommends to use managed tables . but based on use case we need, as mostly for analytics purpose we will be using external tables, we may not avoid that