topic FUNCTIONNING OF QVD FILES in QlikView

FUNCTIONNING OF QVD FILES

Fri, 29 Oct 2010 16:30:21 GMT

Please in the functioning of QVD file, I heard about the incremental load.

I'd like to have a sample script that performs the incremental load.

Thank you

FUNCTIONNING OF QVD FILES

Anonymous — Fri, 29 Oct 2010 17:00:03 GMT

You question is generic, but solutions are always specific. Read "help" and try...
Anyway, I ansewred to a specific question yesterday, you can see an example here

FUNCTIONNING OF QVD FILES

fernandotoledo — Fri, 29 Oct 2010 18:07:25 GMT

The first thing to keep in mind is that every time you use the STORE command, qlikview overwrites your old qvd file.

The incremental load is a sequence of actions where you get the historical data from a qvd, the new data from your source (concatenating) then overwrite the old qvd. You can also create an Insert / Delete logic using dates or primary keys.

The typical incremental load looks like:


//historical data from qvd but today data
DATA:
LOAD * FROM HISTORICAL_DATA.qvd WHERE DATE<TODAY();

//adds new data from today - concatenates to DATA table
CONCATENATE LOAD * WHERE DATE=TODAY(); SQL SELECT * FROM SOURCE WHERE ;

//stores the new table overwriting the old qvd
STORE DATA INTO HISTORICAL_DATA.QVD;

The important is to get the idea, so you can adapt this solution to your case!

Best regards

Fernando