6 Replies Latest reply: Feb 8, 2013 7:53 AM by Stephan Froede RSS

    oracle union in qlikview

      Hi all,

       

       

      I would like to solve the following problem - to me it's a problem anyway.

       

       

      1. I have three datasources that I load data from - source_one, source_two & source_three.

      2. The query I use fetches the same number & types of fields.

      3. Normally I would use a union to organise the data underneath oneanother.

       

       

      Does Qlikview have functionality to do this?

       

       

      ( in Oracle I would do

       

       

      source_one

      union (all)

      source_two

      union (all)

      source_three

       

       

      this is the result I would like to accomplish using Qlikview )

       

       

      Thanks in advance

        • oracle union in qlikview
          Tanel Rüütli

          Concatenate load

          (See QV help for examples... )

          • oracle union in qlikview

            It turns out that QV does an automatic concatenate if the number of fields - and datatype(?) - are identical.

              • Re: oracle union in qlikview

                Rob,

                 

                Yes.

                 

                QV is analysing the fieldnames and it produces a data model out of it, that is cool, but can turn very nasty if ou use QV on a poor data model.

                 

                Because QV is producing a combination out of all prossibilities e.g.:

                 

                Table Rows - Table Fields

                100.000 - 10

                100.000 - 10

                100.000 - 10

                 

                is

                 

                100.000*10 * 100.000 * 10 * 100.000 * 10 -> giant number, because it is a combinatoric approach it is not even linear...

                 

                You can produce billions of combinations out of tiny data, and bring down QV during load and slowing down the UI as well...a full package of fun

                 

                Further depending on the data, you can get circles, QV is detecting them but I am not very sure what they really mean for the data navigation behaviour, so I do avoid them.

                 

                 

                 

                For Union All, Qlik View has a problem understanding them. They do work in SQL Developer but they do not work in QV.

                 

                But chained/concatened load should be used really carefully and with hindsight, it is practical feature but should not replace a proper data model.

                 

                If you use it for just patching together some data to get it done or to avoid data modelling (star scheme) --> that is a bad idea because maintaing QV apps is becoming painful and the behaviour of QV is becoming indeterministic.

                 

                Regards,

                Stephan

                • Re: oracle union in qlikview

                  Rob,

                   

                  Yes.

                   

                  QV is analysing the fieldnames and it produces a data model out of it, that is cool, but can turn very nasty if ou use QV on a poor data model.

                   

                  Because QV is producing a combination out of all prossibilities e.g.:

                   

                  Table Rows - Table Fields

                  100.000 - 10

                  100.000 - 10

                  100.000 - 10

                   

                  is

                   

                  100.000*10 * 100.000 * 10 * 100.000 * 10 -> giant number, because it is a combinatoric approach it is not even linear...

                   

                  You can produce billions of combinations out of tiny data, and bring down QV during load and slowing down the UI as well...a full package of fun

                   

                  Further depending on the data, you can get circles, QV is detecting them but I am not very sure what they really mean for the data navigation behaviour, so I do avoid them.

                   

                   

                   

                  For Union All, Qlik View has a problem understanding them. They do work in SQL Developer but they do not work in QV.

                   

                  But chained/concatened load should be used really carefully and with hindsight, it is practical feature but should not replace a proper data model.

                   

                  If you use it for just patching together some data to get it done or to avoid data modelling (star scheme) --> that is a bad idea because maintaing QV apps is becoming painful and the behaviour of QV is becoming indeterministic.

                   

                  Regards,

                  Stephan

                  • Re: oracle union in qlikview

                    Rob,

                     

                    Yes.

                     

                    QV is analysing the fieldnames and it produces a data model out of it, that is cool, but can turn very nasty if ou use QV on a poor data model.

                     

                    Because QV is producing a combination out of all prossibilities e.g.:

                     

                    Table Rows - Table Fields

                    100.000 - 10

                    100.000 - 10

                    100.000 - 10

                     

                    is

                     

                    100.000*10 * 100.000 * 10 * 100.000 * 10 -> giant number, because it is a combinatoric approach it is not even linear...

                     

                    You can produce billions of combinations out of tiny data, and bring down QV during load and slowing down the UI as well...a full package of fun

                     

                    Further depending on the data, you can get circles, QV is detecting them but I am not very sure what they really mean for the data navigation behaviour, so I do avoid them.

                     

                     

                     

                    For Union All, Qlik View has a problem understanding them. They do work in SQL Developer but they do not work in QV.

                     

                    But chained/concatened load should be used really carefully and with hindsight, it is practical feature but should not replace a proper data model.

                     

                    If you use it for just patching together some data to get it done or to avoid data modelling (star scheme) --> that is a bad idea because maintaing QV apps is becoming painful and the behaviour of QV is becoming indeterministic.

                     

                    Regards,

                    Stephan

                    • Re: oracle union in qlikview

                      Rob,

                       

                      Yes.

                       

                      QV is analysing the fieldnames and it produces a data model out of it, that is cool, but can turn very nasty if ou use QV on a poor data model.

                       

                      Because QV is producing a combination out of all prossibilities e.g.:

                       

                      Table Rows - Table Fields

                      100.000 - 10

                      100.000 - 10

                      100.000 - 10

                       

                      is

                       

                      100.000*10 * 100.000 * 10 * 100.000 * 10 -> giant number, because it is a combinatoric approach it is not even linear...

                       

                      You can produce billions of combinations out of tiny data, and bring down QV during load and slowing down the UI as well...a full package of fun

                       

                      Further depending on the data, you can get circles, QV is detecting them but I am not very sure what they really mean for the data navigation behaviour, so I do avoid them.

                       

                       

                       

                      For Union All, Qlik View has a problem understanding them. They do work in SQL Developer but they do not work in QV.

                       

                      But chained/concatened load should be used really carefully and with hindsight, it is practical feature but should not replace a proper data model.

                       

                      If you use it for just patching together some data to get it done or to avoid data modelling (star scheme) --> that is a bad idea because maintaing QV apps is becoming painful and the behaviour of QV is becoming indeterministic.

                       

                      Regards,

                      Stephan