Same tag group on execution and historical mode

Hello,

I have been wondering if the following is correct, when you are using the same tag group like 1h for query tag execution and the same tag group on historical mode. Is it possible that query takes longer time like 1 second and when tag group executes the save does not save it to database because the query hasn't finished executing when it looks at the value so the value will be saved in the database the next tag group execution time, because of sufficent change and max time being bigger than tag group.

Other thing is on performance. Is the tag group historical mode is more efficent on gateway performance then min-max timers?

Any help insight on this would be helpful.

Thanks