If you would like to know if the site maintenance tasks are running successfully you can either check the site status for errors or use the below SQL query
select *,
floor(DATEDIFF(ss,laststarttime,lastcompletiontime)/3600) as Hours,
floor(DATEDIFF(ss,laststarttime,lastcompletiontime)/60)- floor(DATEDIFF(ss,laststarttime,lastcompletiontime)/3600)*60 as Minutes,
floor(DATEDIFF(ss,laststarttime,lastcompletiontime))- floor(DATEDIFF(ss,laststarttime,lastcompletiontime)/60)*60 as TotalSeconds
from SQLTaskStatus
Completion status – 0 = Success
