Multiple 'instances' of same data but different selections

[#1]

Dear all,

I have the following situation: I have a 'big data' source of about 2 gig of QVD data for one year of data consisting lets say of position information for vehicles. In essence:

Vehicle	Datetime	Position
A	01/01/2013	X
B	01/01/2013	Y
C	01/01/2013	X
D	01/01/2013	Y

....

In need to determine a commun path for several vehicles. This is no problem with qlikview as when I select the vehicles, I recieve the associated positions. However, I need to do this for different Datetimes. Meaning: I need the list of positions of vehicle A on date 01/01/2013 and I need the list of positions of vehicle B on date 02/01/2013 and from those two lists I need the postions which correspond.

Has anyone got a clever idea on how to do this without loading the QVD multiple times?

Thank you and I wish you all a merry Chistmas and a happy new year.

[swuehl · Accepted solution]

Try using a set analysis expression with implicite field value definitions, maybe like

=count( DISTINCT

{<Position = p({<Vehicle = {A}, Datetime= {'01/01/2013'}>})

                    * p({<Vehicle = {B},Datetime= {'02/01/2013'}>}) >}

Position)

Instead of the fixed Vehicles and Datetime values, you can use alternate states to let the user select from list boxes.

Hope this helps,

Stefan

[#3]

Thank you swuehl, that sounds very promising. Now I understand that business about the alternate states...