SQL

oracle parameter

-- SQL Plus:
SQL> SHOW PARAMETER

-- Request
SELECT NAME,VALUE,ISSES_MODIFIABLE,ISSYS_MODIFIABLE
FROM gv$PARAMETER
WHERE NAME LIKE '%processes%';

oracle parameter

-- NLS parameters (session, base, instance)
SELECT *
FROM (SELECT 'SESSION' SCOPE, nsp.* FROM NLS_SESSION_PARAMETERS nsp
      UNION ALL
      SELECT 'DATABASE' SCOPE, ndp.* FROM NLS_DATABASE_PARAMETERS ndp
      UNION ALL
      SELECT 'INSTANCE' SCOPE, nip.* FROM NLS_INSTANCE_PARAMETERS nip) a
PIVOT (listagg(VALUE) WITHIN GROUP (ORDER BY SCOPE) FOR SCOPE IN (
    'SESSION' AS "SESSION" ,'DATABASE' AS DATABASE ,'INSTANCE' AS INSTANCE));
-- ⇓ Test it ⇓ (Fiddle source link)