*** Use of QVD/ Incremental Data Load ***

[IAMDV]

Dear All,

Please can you someone guide or explain me about QVD files? I had read the documentation and it is confusing in terms of loading the data. I would really appreciate if some one can share an example. I have a requirement of loading the data on incremental basis without reloading the historical data.

Many thanks in advance.

[Miguel_Angel_Baeyens · Accepted solution]

Hello,

QlikView has not incremental loads as such. What I do is to create two different QVW files, one that reads the historic data, and store it in QVD files (this file isn't usually reloaded unless there are changes in the data model). Using the WHERE clause of your SELECT statement you can set an easy filter by date, number, code, etc. I create another QVW file, with the almost same exact script, where the SELECTs pull from database the latest data. This file is reloaded say daily. Then, this same file or even a different file where I want to have the charts, I do a load and concatenation of both QVD files (sales historic, sales current, for example) and create the data model.

Using variables for the dates from and to I want to SELECT and scheduling different reload tasks makes maintenance relatively easy.

Hope that helps.

[sushil353]

Hi DV,

QVD is a data file of qlikview. as qvw file contain application and data on the other hand qvd saves data in binary format. you can't do incremental load on qvw file so for that qvd file comes into play..

you can append fresh data to the previous qvd file using store <table name> into <filename.qvd(qvd)> and concatenate with the existing qvd. you can aply where condition in select statement which is your constraint for the history...and you can automate the loading using batch file..

hope it will help you to understand

[#4]

Hi DV,

See this. It may give you an Idea

[View:http://community.qlik.com/cfs-file.ashx/__key/CommunityServer.Discussions.Components.Files/11/2746.Incremental_2500_20Load.ppt:550:0]

[#5]

This link answers most of the questions you have on QVD.

http://community.qlik.com/blogs/qlikviewblogs/archive/2011/02/17/qvd-questions-and-answers.aspx

[IAMDV]

Miguel - That is good idea. Thank you very much for detailed explanation.

Sushil - Thanks to you as well for taking time to explain me. However, I am confused now... I might be silly to ask you this question. But what is the difference between Incremental Load & Appending Frest Data. I thought both are same???

Also can you provide sample script? That will be really helpful!

Sravan - Thank you very much for the presentation. It is very helpful reference, however I need to understand few concepts before digesting the content of presentation.

______________________________________________________________________________________________________________________

I have a dataset which is around 35 million records with 12 columns and I wanted to know the best practices to speed up the document? Can I load the data to QVD File?

Many thanks for your patience and help!

[sushil353]

hi DV,

http://global.qlik.com/uploadedimages/QlikLearn_UnderstandingQVD.pdf

check this out.. it is very good for understanding

[IAMDV]

Thanks Sushil. Muralidhar Koti just provided the same document along with a video by Rob. I am looking in to this now and I'll come back with more questions.

Thanks folks!

[farolito20]

Do you have any example?

[Anonymous]

the page come with the error:-

The item does not exist. It may have been deleted.

please help me out for this