11 Replies Latest reply on Sep 8, 2019 11:06 PM by mortenbodaugaard.jrgensen

    Where's the Data Stored?

    Sara Lemme

      I'm working with Information Security at our institution, and have run into some questions about exactly where data is stored - on the app server or in a secure database - when visualizations are published to Tableau Server.  Here's my current understanding of what happens - is this correct?

       

      1. When a Tableau Workbook has a live connection to a data source, and the visualization is published to Tableau Server, no data is stored on the server.  A live connection is maintained with the (in our case Oracle) database.  Is this accurate?

       

      2. When a Tableau Workbook has a data extract, and the visualization is published to Tableau Server, the data extract is stored on the server.  Is this correct?

       

      Your assistance is greatly appreciated.  Thank you!

        • 1. Re: Where's the Data Stored?
          lei.chen.0

          Hello Sara,

           

          I've moved your post to Server Administration , where I believe your questions will likely get more replies.

           

          As for your questions,

           

          1. Not really

           

          Please refer to this onlinehelp Configure Data Connections

           

          2. Yes

           

          As for the extract location on server, please refer to this post Storage location of Extract in server?

           

           

          Regards

           

          Lei

          • 2. Re: Where's the Data Stored?
            Sara Lemme

            Thank you, Lei!  Some helpful articles and the right place for my question.

            • 3. Re: Where's the Data Stored?
              Obed Tsimi

              any other clarification needed?

              • 4. Re: Where's the Data Stored?
                Sara Lemme

                Hi Obed,

                 

                I think I am understanding now...

                 

                -Live data connections, when published to Tableau Server, create a cache of data on Tableau Server.

                 

                -Connections to extracts, when published to Tableau Server, store the extract on Tableau Server.

                 

                If you have any additional information of note, or corrections to my understanding, let me know.  Thank you!

                • 5. Re: Where's the Data Stored?
                  Obed Tsimi

                  Bravo, you got it!

                  Don't hesitate to reach out if you have further questions or concerns.

                  • 6. Re: Where's the Data Stored?
                    jennifer.bielak.0

                    Does this create a security issue?

                    If the Live connection stores a cache and I don't have access to the database, am I able to see the cached view?

                    Likewise with extracts. If I don't have access to the published extract data source, can I see a view that is cached in a workbook that connects to the extract?

                    • 7. Re: Where's the Data Stored?
                      Obed Tsimi

                      Good questions Jennifer.

                      No, it does not constitute any security risks there. The same permissions would apply. Cached views are not independent of permissions.

                      As far as the extracts, those views are not cached. Even if they were, permissions would still apply and only able to see what you have permission to.

                      1 of 1 people found this helpful
                      • 8. Re: Where's the Data Stored?
                        Sara Lemme

                        So I have another line of questions coming from the IT side of our institution, and I'm hoping you all can assist me in finding good answers.  I have sent the documentation from https://onlinehelp.tableau.com/current/server/en-us/config_cache.htm in my initial email response to them.  Here are their questions:

                         

                         

                        1. As for the cached data, may we reach out to Tableau to determine if the cached data are used for performance improvement similar to most other AppServers where cached data has limited lifespan.  Or is this a variation of cache where the data is stored permanently on the AppServer until it is manually refresh or remove by the operator?
                        2. Depending on the finding from number 4, we may also entertain the option disabling the cache.  Naturally, we do want to properly assess the performance impact of such option.  We certainly would not want to introduce major impact to Tableau’s performance. 

                         

                        Based on the article I mentioned above, it looks to me like we can configure the Server to not keep data in the Cache for very long by using the "Balanced" setting.  Hopefully that means we won't need to go down the road of disabling the cache.  Is it even possible to disable the caching in Tableau Server?

                         

                        Also, does anyone know if, with an enterprise license, we can run a separate development server without purchasing anything additional?  I've also asked our Tableau representative - just wondering if you have any experience in this area.

                         

                        Thank you!

                        • 9. Re: Where's the Data Stored?
                          Obed Tsimi

                          Hello ,

                           

                          1. Cache server cannot be disables and it is indeed used for performance improvement as most webapps and has a limited lifespan by what you select under data connections.

                           

                          As far as licensing, with your Tableau license, you are entitled to also have a DEV environment with the same key without any additional fees.

                          Licensing a Tableau Server Test Environment | Tableau Software

                           

                          Thanks

                          1 of 1 people found this helpful
                          • 10. Re: Where's the Data Stored?
                            Haya mohiyaddin

                            Hi ,

                             

                            I have a requirement in which the data is changing real time based on the input from a web application.

                            If I connect to that table and create a live connection and develop a static view with few columns ,will it change the view exactly when new data is updated?.

                             

                            We are planning to embed the visualization in same web application. Since I do not have any filters in my static view pivot visualization will it always show the data from cache? (as i am not changing any filter and query is not sent to database) Or will it have to wait till server refreshed the cache?.

                             

                            To summarize my question will tableau can display live streaming data  ie , will it display the data content as soon as there is a change in data or does it have to wait till the cache is refreshed?.

                             

                            Regards,

                            Haya

                            • 11. Re: Where's the Data Stored?
                              mortenbodaugaard.jrgensen

                              You can disable caching, either server wide or using a URL-parameter.

                               

                              So you can have a live connection which can be refreshed to get the most recent data.