cache should be cleared to run new experiments even if the changes are in the database block.
from What I understood from the documentation of beat.editor about cache system, it seems that if you change something in a block, beat should rerun that block and all the blocks depending on it. But it is not the case. I changed the root folder for the database atnt/5 in the prefix given in beat.tutorial.prefix to run the experiment test/tutorial/eigenface/1/atnt , but I had to clear the cache, otherwise it would still point to the wrong address for the database, even-though the json file was updated immediately.