How to check daily redo generation in Oracle

Count log switches and total archived redo (MB) per day since V$ARCHIVED_LOG started tracking. Baseline for FRA sizing and picking the right online redo log size.

SELECT TRUNC(completion_time) AS logdate,
       COUNT(*)               AS logswitch,
       ROUND(SUM(blocks * block_size) / 1024 / 1024) AS "REDO PER DAY (MB)"
FROM   v$archived_log
GROUP BY TRUNC(completion_time)
ORDER BY 1;