5 Replies Latest reply: Jan 11, 2011 2:01 PM by amey_churi RSS

    Qlikview Files Backup Strategy

      Hello All,

      We are trying to implement Qlikview solution for our reporting needs. We will be having incremental loads using QVD files. So we will be having both QVW and QVD files holding current data. In such cases, is it required to take back ups of both files? Can anyone who has experience with similar case can share or suggest backup strategy?

      These QVD files may reach to 2-3 GB.

      Any reply is appreciated.




        • Qlikview Files Backup Strategy
          John Witherspoon

          I'd think in terms of what would happen if you lost one or the other.

          If you lost the QVW but not the QVD, you might have the data, but it isn't accessible until you rewrite a QVW to retrieve it and display it. The time to write all that code again is very expensive compared to the cost of disk space. So back up your QVWs.

          If you lost the QVD but not the QVW, in trivial cases it would be easy to rebuild the QVD - binary load the QVW, and write out all the tables as QVDs. But for that to work, you must have at least one QVW that reads in the ENTIRE table and does NO manipulation of it. In almost all cases in our shop, we manipulate the data as we read it in, we skip fields we don't care about, date ranges we don't care about, and so on. There would be no way to recover the raw data from any of the QVWs. So back up your QVDs.

          If you really, really can't afford the space, you could probably drop all the data from the QVW before backing it up so that you were only storing the important bits - the script, the objects, the macros, that sort of thing. I'm not sure exactly how you'd go about doing that cleanly and easily, but I'm sure it could be done. But even then, I'd think the extra trouble would cost you more than just buying more disk space.

          I am not personally involved in our backup strategy, so I don't know what it actually is, and I may be missing a clever way to save storage space.

            • Qlikview Files Backup Strategy

              Hi John,

              Thanks for your advice. I understood now that backing up QVW is a must. I believe we will be mostly scheduling jobs to incrementally load QVDs and then another job to refresh dashboards referring to those QVDs (I hope we will be creating dashboards simply referring to specific fields in QVDs instead of creating QVDs with limited fields from source tables). In that case, if a QVD gets corrupted, I can just create another one as we have backups of all data warehouse tables. And then just manually refreshing associated QVWs should do the trick.

              In that case, backing up QVDs looks like overhead. We will surely have space to hold at least one backup of QVW.

              Let me know if I'm thinking in right direction.