We are in the design phase of our QlikView project and I was wondering if anyone has had the same issue regarding archived versions of QVWs run at a particular date:
Our main data set is sent each evening to an SQL database - from there individual QVD files are generated (overwritten) and then after this individual date-stamped QVW reports are generated from these QVD files.
This effectively means that for each QVW that we have developed, there are multiple date stamped copies of this QVW run over the data set in the QVD file(s) at that point in time.
I can't help thinking that this is not the most efficient (or correct?) way of dealing with this issue of accessing QVW reports run 'as at' a particular point in time.
I assume that the other option is to CONCATENATE data into the QVD file each evening and have only one version of each QVW which may be accessed via a 'Run date' key field....?
Does anyone have any opinions/recommendations/warnings regarding either or both of these solutions?
You probably can redesign your apps that you create and load QVDs that contain all historic data as well as the current data (if that's what I think you are talking about).
I think it's more a question what you want and need to achieve:
- just archiving your final QVWs as unchangeable snapshots
vs
- implementing a mechanism to store, retrieve and possibly filter all historic data, so you might be able to also reload the app with the data from a previous point in time, maybe with changed logic
It may also depend on the question if you may be able to retrieve the historic data from the source SQL DB or not.
I have to say that in the past I have archived my QVD files but never my QVW files. I am not sure that your method is wrong per se but I have never done that.
The difficulty or good aspect (depending upon perspective) is that the application is likely to change over time and the reports are likely to change too. Some of this may be change in data/change in formats so your old data may not run with your newer systems. As a result you may need to have multiple versions of the QVW as well as QVD........
Despite this I would still tend to lean towards storing the QVD rather than the QVW and use a run from date type of function as stated above.
The only other bit to think about .... Is this data still available in the SQL database? If so change the load process so that it can load historic data
