1 Reply Latest reply on Apr 25, 2018 2:56 PM by Patrick A Van Der Hyde

    Changes made to a re-published data source are not visible - assume this is a cache issue...

    Donna Coles

      VERSION : v10.1.

      Data Connections Caching : Refresh less often

       

      BACKGROUND

      The vast majority of our data sources are published data sources on Tableau Server that connect to a SQL Server.  Some are extracts, some are live connections.  This issue is related to when changes are made to data sources with live connections.

       

      ISSUE

      A new field [Cost] was recently added to an existing data source.  The change was made to the SQL View on the SQL Server that the published data source connects to.  The new field was visible in the data source if a user created a new workbook online (via web editing functionality) or connected via Tableau Desktop.

       

      The field needs to be renamed to [ESI Cost].  The change was again made to the SQL View on the SQL Server.  Some default formatting was also required, so I downloaded the data source from the server.  The [Cost] field was no longer present, but [ESI Cost] was displayed as expected.  I applied the formatting changes to the data source and re-published to server, over-writing the existing data source.

       

      If I connect to the data source via the web editing facilty, the [ESI Cost] field is shown but with a ! displayed and it can't be used.

      If I connect to the data source via Tableau Desktop, the [Cost] field is still shown.

      If I re-download the data source and open in Tableau Desktop I can see the [ESI Cost] field and query it with no issue.

       

      I'm assuming its to do with server caching, but a lot of the documentation I've read talks about views/workbooks and how 'clicking Refresh Data' will force a retrieval of new data.  But I'm not working with an existing view, just connecting directly to a changed published data source that is a live connection - there is no 'refresh data' option to click.  Something has a handle on the definition of the data source and I want to know if I can 'force' it to get the latest version, or just have to wait an unknown period of time for it to sort itself out/the next day after the service restarts following our backup/restore routine.  It's not a major issue, just a bit frustrating when you're trying to make simple changes for users to validate.

       

      My personal feeling is that republishing the data source should clear anything in cache, but obviously I'm not seeing this.

      I've noticed this issue a few times since we moved to v10.1 15 months ago in Jan 2017, but never fully understood exactly what is happening, so reaching out for some advice.  I don't recall ever having this when we were on v9.  Changes to existing data sources are not that frequent, and usually are additive only (new fields added), rather than fields renamed.  I have noticed new fields don't always immediately appear either.

       

      I've checked the known issues/release notes and can't see anything related to this.

       

      Any insight appreciated - is this actually expected behaviour?

       

      Thanks

      Donna