- We have noticed that data loads into QlikView Personal Edition can silently fail.
- That is, when we press control-R to reload data from a SQL Server database, we have seen cases where not all data is loaded, but no error message is displayed. We only notice this by carefully comparing counts of number of rows loaded versus counts in the corresponding database views.
- We have a .qvw file, which is storing data to .qvd files.
If you could exclude conditions-reason in where-clauses and changes in the database after loading from qv it could be that a very high workload on the database and/or temporary missing network and/or error-values in certain records caused the missing records. Normally it should give a breakdown or an error-message but it must not if for example the data-connection-driver relativ fault-tolerant.
You should enable the load-logging (with timestamp). Here you could see the count of loaded records and also the appropriate time-spent. Often need such silent fails more or less time.
I suspect high workloads on the database are not the cause, because these are development databases with few or no users. Intermittent network issues could be a cause, but they would be hard to pin down. Issue is that if there are problems the load should fail. If it did, we would be happy. Where it causes a problem is if there is no error, but still missing data.
We did enable load-logging and watch the count of row, which is how we had to troubleshoot when we realised what was happening.
I don't know if this is the case, but many times my load processes (via Script) fail because of some file being hold by the system due to a previous wrong ending.
Nothing will be lost if you inspect this situation.
What show the log-files? Could you compare the data in the database and which qv loaded - which records are missing? Some values (errors or special chars) in those records could be problematic.
Are there any aggregations, where-clause or joins in this load? A reduction of the complexity an doing this later in further load-processes could avoid problems with the workload and made it easier to find any differences.
Sometimes is it useful to separate such data and loads in dummy databases/applications and runs these with higher frequency and/or with various parameter could lead to the cause of your issue.
The problem is intermittent and rare, so I cannot reproduce at will. We will attempt to capture log files corresponding to the failure when we can catch it, but I don't expect this will be quickly.
The load is simple. It only uses load, select and store statements. There is one case statement in one of the select statements. We'll try to remove this in case its related, but I doubt it.
Using the QlikView 11.20 [and other versions] Desktop I have noticed that it appears to have some kind of sticky cache, which I posted as a discussion - albeit with no replies.
