If you closed the workbook and reopened it, you may need to refresh the connection. Click on the Data menu, navigate to the data source and select Edit Connection... then re-navigate to the source to establish a live connection.
Hope this helps!
Tableau Server data caching has some glitches. If you update a table in your DB, say with a new or dropped column, you may not be able to get Tableau Server to see the updates without stopping and restarting Tableau Server. This happens to us occasionally with Oracle, there is no good workaround, we have to wait for our nightly restart of Server for our views to be fixed. We have never seen this problem in Desktop however, so if you are, something else sounds wrong.
What setting do you have on this screen?
We had to set ours to "refresh more often" but I've never encountered a cache holding until the server restarts before.
We currently use "refresh less often" but even with "balanced 120" we've had this problem for years. It's not that we see old data, it's that we see an old structure for the table itself, which means our newly published views won't even load until the next day after the restart flushes the cache. Truly maddening. Sometimes this means we only make table changes at the end of the working day. An option in Server to flush the cache without restarting Server would solve this. We can't restart in the middle of the day without bumping users.
We have this problem too. It would be great if Tableau would add a new "tabadmin dump cache" command that would enable us to dump the Tableau cache on-demand from the command line. We have regularly scheduled data loads (more frequent than daily) that invalidate the cached query results in Tableau. Currently, we can only:
1) Set our cache settings to "Refresh More Often". This always returns accurate data, but has a HUGE impact on performance.
2) Set our cache settings to "Balanced". However, whatever value we put for "minutes" is translated as "this is how long we're ok with our users viewing stale data", which doesn't really give us a warm fuzzy feeling.
3) Set our cache settings to "Refresh Less Often", and schedule a RESTART OF TABLEAU SERVER just after each regularly scheduled data load. This is great, except it takes NEARLY 5 MINUTES for our HA Tableau environment to restart, and our users get 500 errors if they attempt to view reports while the restarts are happening.
What would be SPECTACULAR is if we could dump the cache from the command line after every data load. I'm guessing it would take a lot less time to just dump the cache versus restarting the entire tableau infrastructure...