2 Replies Latest reply: Dec 13, 2016 6:57 AM by Matheus Colares RSS

    Doubt about load .qvd

    Matheus Colares

      Hi folks,

           I'm with a doubt...I'm was studing, reading post on qlikview community to find how load faster a .qvd very big, and i found a post wicht the man did like this:

       

      set vDadosFinais = 'MOVTO_VDADET';
      load * from ..\..\Qvds\$(vDadosFinais).QVD (qvd);
      

       

      So, that way i get it make a load took time 15 min, load in 1 min...Very cool...but i not understood what i did, why this works better and what is the diference make that , and make like this:

       

      load * from ..\..\Qvds\MOVTO_VDADET.QVD (qvd);
      

       

      If someone knows the answer , can explain me?

       

      Thank you.

        • Re: Doubt about load .qvd
          Gysbert Wassenaar

          I doubt that only changing a literal text string into a variable will have the effect of speeding up a load by a factor 15. What can help is not doing anything that prevents a qvd from loading in optimized mode. See this blog post for more information: https://www.quickintelligence.co.uk/qlikview-optimised-qvd-loads/

          • Re: Doubt about load .qvd
            Marcus Sommer

            Both of your example-statements does the same and will have the same run-time (the differences within the path aren't important for the run-times unless one is loading from a fast storage and other from a slow network). What do you noticed is difference between a normal qvd-load and an optimized qvd-load. By an optimized load happens no (real) processing of the data - they will simply transferred within the RAM. A qvd is nearly exactly a 1:1 image from RAM. In this way is only allowed to rename fields and to use a where-exists-clause with a single parameter - all other transformings will need some processing and therefore prevent the optimized load.

             

            - Marcus