topic Re: QVDs in QlikView

QVDs

Fri, 04 Oct 2013 10:15:36 GMT

Hi all,

I have a small doubt regarding QVDs. Is it mandatory to create QVDs particularly when you have small volume of data, lets say 100,000 rows ? As I know QVDs has many benefits and one of the reasons that QVD is to create for faster performance. What if I avoid QVD and directly connect to a database to develop an app with small volume of data?

Your suggestions will be greatly aprreciated.

Thanks

Re: QVDs

ngulliver — Fri, 04 Oct 2013 10:21:07 GMT

Hi, Prakash.

It is not mandatory. Usually it is done for efficiency purposes if you are creating something with a lot of data or regular use.

If you are putting something together for a quick demo or have really small amounts of data then it is not worth doing unless there are problems linking to the database.

Regards,

Neil.

Re: QVDs

Fri, 04 Oct 2013 10:25:18 GMT

Hi ,

Just the other day, I loaded a qvw with more than 5 different sql statements,each with some join and where conditions.

And, two of them touch a table with about 1.3 crore rows.

The entire report loaded in about 30 minutes. I did not use any qvd files.

So, 1 lakh rows should not be a problem.

Regards,

Anju

Re: QVDs

dmohanty — Fri, 04 Oct 2013 10:28:37 GMT

Hi Prakash,

Incase your source table gets refreshed, let say 3-4 times a day, its not a good practice to hit the databse over and over in a day.

In this scenarios, QVDs are helpful and you can use incremental reload if you dont want to reload the full set of QVDs again. For the transaction/table refresh that happens hourly or daily, you can use incremental reload as well.

If some of those source tables are used in some other Data Models, in this case also QVDs are helpful and those can be used for multipurpose.

QVDs will also help while doing the Unit Testing, Debugging.

If you are using your App for practice or demo purpose or a stand-alone app with less records, then you can skip the QVD generation step.

Hope its clear!!!

Re: QVDs

ngulliver — Fri, 04 Oct 2013 12:25:36 GMT

Hi, Prakash.

DMohanty make a good case for when to use QVD generators.

If you are happy with your responses, please close the question , marking an answer as correct.

Many thanks,

Neil

Re: QVDs

Fri, 04 Oct 2013 12:34:25 GMT

Wonderful, Thank you all for your valuable suggestions. Iam developing a real-time app from the scratch by connecting to SQL database which I need fetch about 100,000 rows into Qlikview. I was not clear whether I need to create QVD or not for this volume of data I have. From your answers, I am now clear that I do not need to be create any QVDs for my case.

Thanks

Re: QVDs

Clever_Anjos — Fri, 04 Oct 2013 12:40:21 GMT

Prakash Puli, the question here is if you need to retrieve all 100,000 rows everytime.

Supose you database has "date" field, records from yesterday or before need to be retrieved again? Are they modified?

If not, I would recomend to only retrieve "fresh" records and retrieve "old" one from QVD´s