List views columns in Oracle database

Query

A. All views accessible to the current user

select col.column_id, 
       col.owner as schema_name,
       col.table_name, 
       col.column_name, 
       col.data_type, 
       col.data_length, 
       col.data_precision, 
       col.data_scale, 
       col.nullable
from sys.all_tab_columns col
inner join sys.all_views v on col.owner = v.owner 
                              and col.table_name = v.view_name
order by col.owner, col.table_name, col.column_id;

https://dataedo.com/kb/query/oracle/list-views-columns

List views columns in Oracle database - Oracle Query Toolbox