Do you mean Tableau Server? Then there are ways to trigger an extract refresh,
How often does your database refresh? And how often does your extract refresh? In my world, the most recent data is day old, hence I set up my refresh extracts after my Cron jobs are done. Then there's always "Run Now" option. If the data size isn't that big and no performance constraint "Live" is another option. Just throwing ideas out there, see which works best for you.