Analytics Software

If you are interested in using cascading parameters in Discoverer, there is a gotcha that you have to watch out for. I have run into this in Discoverer 10.1.2.2. The Discoverer Plus manual states that worksheet items in the cascading parameters must be in the same item hierarchy and must have a list of values (LOV). Well, I had those requirements satisfied, but when I picked a value for my first parameter and then clicked on the LOV icon for the second parameter (so the list of available values to show would be smaller, based on the first parameter's value), the retrieval process would spin and spin and spin and time out. I pushed my filtering time out up to 5 minutes and it would still time out. Logged an issue with Oracle support and no quick answer. So I kept playing around. I noticed that the process worked fine on another hierarchy. Finally realized that I had a join defined in the business area between the two master tables where this process worked, but not between the two where I had the time out problem. I have a large table, so I had built the LOV item classes off the smaller master tables, as the documentation suggests for performance reasons, and had joined the large folder to the smaller folders, as the documentation said to do. But nowhere in the documentation did it say that for cascading parameters that you have to have a join defined between the tables involved in the hierarchy. I had not needed to define joins for the hierarchy since I had a custom folder and the items all existed in that one folder (very much like the video store tutorial, where region and city items are in the same folder). So I created that join definition in the business area between the two master tables. I went back to my workbook and recreated the cascading parameter definition. Voila. Works like a charm now. So something to watch out for if you want to do cascading parameters.

John Dickey