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Store and compare previous data set

Hi, i would like to ask it is possible to store the previous data set when there is new data set upload? will it override the old data? and if it is possible to store, can I compare the 2 data set ?? for example able to analysis the difference in the budget from the old data set. thanksSmiley Happy

11 Replies
MVP
MVP

Re: Store and compare previous data set

Sure, you can store your current data to QVDs after each reload (at the end of your script) and then use these snapshot QVDs to run your analysis.

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Re: Store and compare previous data set

Hi Swuehl, thanks for reply, could you give me an example or explain the QVD more details?

MindaugasBacius
Valued Contributor II

Re: Store and compare previous data set

MVP
MVP

Re: Store and compare previous data set

This explains how you can store all tables in your model to QVD:

Storing all tables in Qlikview file to QVD

Maybe what you want to achieve is something similar to an incremental load, so here is an example for that (also explained in the reference manual):

http://qlikviewcookbook.com/download/delta-load-template/

Some more details about QVDs:

QVD Questions and Answers | Qlikview Cookbook

Not applicable

Re: Store and compare previous data set

Hi Mindaugas,

Thank you for sharing the great blog

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Re: Store and compare previous data set

Thanks for the links, I have learn how to store tables to QVD. But how can i use it to run my analysis?

For example, last month my data is:

ProjectStart DateEnd DateBudget
A1/7/20168/10/20171000
B1/3/20161/9/2016500
C1/2/20161/8/2017600
D7/12/20161/8/2017700
E6/8/20161/3/2017800
F1/7/20161/11/2017900

This month, i make changes:

ProjectStart DateEnd DateBudget
A1/7/20168/10/20171000
B1/3/20161/9/2016600
C1/2/20161/9/2020600
D7/12/20161/8/2017700
E6/8/20161/3/2017400
F1/7/20161/11/2017900

I would like to alert that there is change of date and compare the Budget between this 2 months in the dashboard.

MindaugasBacius
Valued Contributor II

Re: Store and compare previous data set

I suggest you to make a flag while storing the data into QVD.

Like every time you save data to QVD add new field today() as Indicator to the new table.

  1. Load the QVD
  2. Make changes to the data resident QVD.
  3. Add Indicator.
  4. Store to the same QVD.

In this scenario you will have the history.

MVP
MVP

Re: Store and compare previous data set

Not applicable

Re: Store and compare previous data set

Hi Mindaugas,

Thanks for your suggestion. I am totally new to the concern of QVD. May I know how to make changes to the data resident QVD? and when I store to the same QVD, how to ensure that it will not override the previous data? Thank youSmiley Happy

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