How to reduce data from prevously created QVD file.

[deepakqlikview_123]

Hi Folks,

Can you please tyell me.

How to reduce data from prevously created QVD file.

Does transformation helps in this case if  yes how it can help.

Thanks

[DavidFoster1]

Do you mean how to read from QVDs and not return all the rows?

[sudeepkm]

when you load data from QVD you can use the where clause to restrict what data you want to load.

Most of the time the QVD load where clause have time related restriction. for example you have QVD generation incremental and it only hold past 12 months data so each month automatically when you load data from QVD you can use the where clause to restrict to past 12 months only.

[DavidFoster1]

A trick I use to allow the QVD load to remain optimised is to load an inline table with the list of values I want to return data for (a specif region, a set of dates, etc, etc) and then I can use 'WHERE EXISTS' syntax which is permitted in optimised loads.

[deepakqlikview_123]

while generating qvd is is possible if i want records only after year 2012.then is is possible to reduce number of records.

Thanks

[tresesco · Accepted solution]

Have you tried simple where clause like:

NewTable:

Load

          Year,

          OtherField

From <OldQvd> Where Year>2012;

Store NewTable into <>;