Open dashboards are not static, they automatically refresh to make sure the current data are displayed. Here is an outline of the refresh logic:
- an open dashboard checks for updates to its reports every minute. If there is a new set of results for any of the reports, any changes to existing reports or new reports added, these changes will be reflected immediately
- each report caches its data for 2 hours and its query would not be re-run unless the data exist in cache - this means, that an open dashboard would never display data older than 2 hours
- a dashboard or any of its reports can be forced to re-run the report query/queries at any time using the "Refresh" action from the report or dashboard dropdown menu - this will re-execute the report's query and update the cached results (for all users)
- the dashboard results are cached for all parameters accessed - you will notice that switching back to a combination of parameters accessed recently is faster, as the report queries are not re-executed and the cached results used instead
- Any published dashboard will be kept updated (pre-warmed) every 2 hours for the default filters, so accessing it is fast as the values are already present in the results cache
With this, you can put a dashboard on a TV on a wall and the dashboard will keep itself updated.