OBIEE Difference between two rows

Found this one on the OTN Forum:

http://forums.oracle.com/forums/thread.jspa?threadID=692479&tstart=30

Handy when your database doesn't have a Lag or Lead function

Till Next Time

OBIEE Duration between events

OBIEE doesn't have a default GANTT type chart type.





For a customer I developed a simple and crude alternative.
First I get the LAG column and a Dummy column which calculates the total duration in the selection so far:

Then a select a vertical bar graph in which I give the dummy column the same colour as the background:


I know it's crude, but it works, but any better suggestions are welcome.