In this article I would like to talk about Chasm traps and Fan traps. These are problems that we often experience while building universes and reports. When encountering these traps, one may wonder what is going on? How come my sum statements arent adding up correctly? Or why am I missing some rows? A properly designed universe will help avoid these problems. In addition, a good understanding about measures and contexts from report designers will help as well.

Chasm Traps

Let’s talk about Chasm traps first. In short, a Chasm trap can be imagined as a bottomless pit where some rows may unknowingly fall in and never come back out. So when viewing a report caught in a Chasm trap, one may ask “Hey where did Record X go??”.

Proper content management planning is a critical element in the design process of a Business Objects enterprise system, unfortunately because of tight deadlines and lack of experience, many times there is not enough time spent here and users are left with a system that’s unorganized and tough to maintain.

I have experienced this first hand so I would like to write about some simple measures to take in order to plan your content.

With calculation contexts in web intelligence we are able to generate powerful reports quick and easily.

Let’s take an example where we have the following dimensions (year, quarter, product) and measure (revenue).

We can easily build a table to represent the sales revenue for each product in that quarter and year.

Now what if we wanted to display the sales revenue in a different context. For example we might want to display the highest quarter’s revenue each year.

You can add an aggregate row that happens after each year and retreive the highest quarter’s revenue from there.

One of the major issues I’ve encountered with Xcelsius 2008 was refreshing too many Live Office components on load from the Data Manager. This would cause the browser to crash when loading the swf.

I’m not sure if it’s a bug but a workaround I discovered was to use a Reporting Services Button to perform the refresh on load. You can find the button in the Web Connectivity components category.

When dealing with a lot of live office objects here are some simple rules to follow.

1. Only use the Refresh on Load from the Data Manager to refresh cells that contain data for objects such as dropdown selectors.

2. Chart data for example that needs to be refreshed on load should be done through the Reporting Services Button

I’ve also attached a Whitepaper from Business Objects that talks about the Refresh on Load from Xcelsius 2008.

Download White Paper

In short, when refreshing on load from the data manager, data is refreshed while the objects are rendering which may cause an overload on the flash player. Whereas refresh on load from the Reporting Services button will occur after all the components have been rendered.