Way to giving preference which callback is carried first

Hi there!! First the community is awesome with so much people ready to answer questions. This time i am using a callback function to read the data from sql and saving it in csv and expect that the whole program data is fitted in that csv for faster data exchange instead of JSON which increases the load on the user side. But the callback of other functions happens simultanously which makes them read the old data keeping the whole program one process behind. Is there a way to give preference to the data collecting callback the trigger the other callbacks.

Thanks in advance for the help.