How is a QVD header formed?

richnorris — Fri, 03 Sep 2010 16:36:25 GMT

Hi there,

We've been having some issues with our QVD extracts running when they should not. We have a check in place to see if they have already run today:


Let vLastRun = date(QvdCreateTime('D:\Qlikview\Core\QVDs\TH_FI.qvd'),DD-MMM-YYYY);
let vNowDate = date(now(),DD-MMM-YYYY);
Let vLastRun = if(isnull(vLastRun),date(now()-2,DD-MMM-YYYY),vLastRun);
TRACE $(vLastRun);
IF $(vLastRun) = $(vNowDate) THEN
 TRACE Data extract has already run today;
 EXIT script;
ELSE
 TRACE Data extract has not yet run today;
END IF

However, on very rare occasions, whats happening is the vLastRun is coming through as null, (even though the QVD definitely exists) and so the extract is re-running. The QVD certainly exists, we have other processes that depend on it that run fine, so the only reason I can imagine that it gets a null is because the header of the QVD is not written properly, so it cant get the 'QvdCreateTime' properly. Does anyone have any information on how I could I could investigate the issue, eg, how and when the headers are formed? Thanks!

topic How is a QVD header formed? in QlikView

How is a QVD header formed?