The fields filearchive.fa_deleted_reason_id and filearchive.fa_deleted_user are never read in SELECT and should be removed as unused.
If necessary the value should be used from the log entry, like done for normal page deletion as well.

If the user field is not dropped, it could be converted to actor (T29615) or at least must be unsigned to hold all possible user.user_id values.

This may not needed if image tables are refactored - T28741

fa_deleted_user - https://codesearch.wmcloud.org/search/?q=%5Cbfa_deleted_user%5Cb&i=nope&files=&excludeFiles=&repos=
fa_deleted_reason_id - https://codesearch.wmcloud.org/search/?q=%5Cbfa_deleted_reason(_id)%3F%5Cb&i=nope&files=&excludeFiles=&repos=