Blackboard Vista tracks student activity. This tracking data is viewed as a critical feature of Vista. Our instructors depended on the information until we revoked their ability to run reports themselves due to performance issues. Campus administrators can still generate reports (though some still fail). We doubt the solution to this is Blackboard improving the queries to create the reports. We favor deleting tracking data (data preserved outside of Vista) to resolve the performance issues.
We developed SQL reports to look at the tracking data where the user in question was not a student. Yes, the data is limited, but in determining when and where a user was active, can help determine where to look in logs. When we hit the performance issues we started using these reports where the user interface reports failed to generate.
My understanding was the user interface and SQL reports on tracking were the same. Both looked at the same data. The user interface reports were just sexier wrapped in HTML and using icons. I compared a user interface report to a SQL report. Just prior to doing this, I was thinking, WebCT was stupid for not tracking when students look at the list of assessments. Turns out “Assessment list viewed” was tracked in the user interface all along but was missing in our sqlplus queries. WTF?
The data has to be there. The problem has to be our approach in sqlplus is inadvertently excluding the information from the reports. Because these reports must be accurate, I’ll crack this nut… Or become nuts myself.
CRACKED THE NUT: So, part of the data WebCT collected was the name of pages. There is a page name table which was inner joined to the user action table. So pages without a name were not reported. George suggested an outer join. I placed it on the page name table which now lets us see the formerly missing tracked actions. For the specific case where I found this, I now get all the missing actions.
Considering a Blackboard (it’s their problem now) feature request to ensure every page in the application has a title. I consider it developer laziness (someone else said worthlessness) that some pages might not have something so core and simple.
ANOTHER TRICK: Oracle’s NVL function displays a piece of text instead of a null value. Awesome for the above.