Row_based qvd optimized

[sunny_talwar]

Hi Team -

I was loading something from a qvd and saw this:

I have seen (qvd optimized), but not row-based qvd optimized. Is this new? What is the difference between qvd optimized and row-based qvd optimized?

Thanks,

Sunny

[rwunderlich]

I think what you are seeing is just a new message. "Row based" QVD is the traditional QVD. For a while, Qlik Sense flirted with a "column based" QVD format. Sense 2 is now back to the row format.

QV12 can read either row based QVDs (created by QV11, QV12, Sense 2) or column based QVDs (created by Sense 1).

I believe the message is only telling you which format of QVD was detected.

-Rob

http://masterssummit.com

http://qlikviewcookbook.com

[sunny_talwar]

Rob - thanks for your response.

What exactly does it mean that a qvd was created row based vs. a qvd was created column based?

[rwunderlich]

It's the internal format of how the data is arranged for performance reasons. I think the only product that produced column based QVDs was Qlik Sense V1. As a practical matter, we as QV developers only care about this for compatibility concerns. You don't get to choose one format or the other. QlikView 11 can't read column base QVDs and therefore can't read Qlik Sense V1 created QVDs (V2 ok). QV12 can read both column and row QVDs, so no issue.

I'm surprised that they even bothered to put "row based" (since it's the default that requires no extra processing) in the QV12 message, but perhaps I'm overlooking something. Maybe someone who knows more about this than I do will chime in.

-Rob

[hic · Accepted solution]

The new 'row-based qvd optimized' is the same as the old 'qvd optimized'. So, looking at the current situation, it was totally unnecessary to change this message.

However, for the future, the message may serve a purpose: We still haven't completely ruled out the possibility of a 'Column-based qvd optimized' load, which probably would be even faster than the current load. But due to backward compatibility challenges we need to think more about how to introduce this.

HIC

[sunny_talwar]

Thank you Henric Cronström‌ for your clarification on this topic.

Best,

Sunny