Determine current notification status

You are given two tables about members' push-notification settings. Table 1: `status_snapshot` - `member_id` INT - `status` STRING — either `'on'` or `'off'` This table stores each member's latest known notification setting as of `2020-01-31 23:59:59 UTC`. Table 2: `actions` - `member_id` INT - `action_date` DATE — UTC calendar date between `2020-02-01` and `2020-02-29` - `action` STRING — either `'turn_on'` or `'turn_off'` Assumptions: - Each row in `actions` is a notification-setting action that occurs after the snapshot in `status_snapshot`. - A member can have at most one action per day. - Members may appear only in `actions` (for example, new members created after the snapshot date). - The member's latest February action determines their final status; if a member has no February actions, keep the snapshot status. Write SQL to return each member's current notification status as of `2020-02-29 23:59:59 UTC`. - Output columns: `member_id, current_status` - Include every member who appears in either table. Follow-up: Suppose `actions` no longer contains `action_date`. Under the assumption that every recorded action is a valid state transition from the member's previous state (so contradictory repeated actions such as `turn_on` when already on do not occur), write SQL or describe how you would infer the final status as of `2020-02-29` using only the snapshot plus the multiset of February actions.