Cache options > Purge the results cache > what to do?

Good afternoon,
A question about the new cache settings:
Purge the results cache when a post is created/updated?

Great when content is not created or updated frequently.

What will this do to a sold out product (so if the product is sold and went from 1 > 0 ?)
I don’t know if I should turn this on or off? Our previous plugin often didn’t update the qty status and the sale prices.

Could you help me?

Kind regards,
Nancy