I am trying to create a schedule; each schedule has many shifts, and each shift has many tasks. The user is able to create as many shifts/tasks as they want. They can modify the tasks by resizing them or moving them to another shift.
When I want to update the schedule, I have two choices:
So my question is this: is it an overkill of MySQL entries if I just delete all the old rows and enter the ones?
It really depends. Are other things referencing your entries, and thus your keys? If so, search and replace is your only option (because you really DON'T want to rebuild indices if you have help it).
If nothing is directly referencing the keys, however, emptying and rebuilding the table is the fastest option available to you.