Yes, Virginia, Narrowcast Segmentation Does Work
Although Santa Claus maybe a myth to some of you, let me assure you narrowcast segmentation does work. I have successfully deployed it on many flash dashboards and large excel reports. In fact, I recently recommended using segmentation for large dashboards in “10 Strategies to Improve your Flash Dashboards Performance.”
I’ll admit that I have attempted segmentation several times before unsuccessfully and I know I’m not alone in this. The fact is most people don’t know when to use it or how to use it. Even after reading through the manuals, documentation, and knowledge base many things remain unclear.
When do you use it?
Personalized page execution on massive document instance sizes. Anything greater than or equal to 150mb on a 32-bit windows execution engine should be considered for segmentation. At these sizes and higher, system performance degrades dramatically and can lead to server crashes. To determine the document instance size monitor a process called MCISM7 via task manager while the service is running. The memory consumed by this process approximates the document instance size.
Another case would be if your service execution spends more time in the slicing phase than in report/document execution. Some causes besides size are numerous personalization’s and or unoptimized segmentation (automatic). In the later case recipients of the same personalization is not grouped together so the same segment executes multiple times.
How do you use it?
Key points not obvious from the documentation:
- The segmentation attribute must be a 4-byte integer
- The subscription ID is the ID form of the segmentation attribute
- You need an information source module where the segmentation attribute is the subscription ID
- The end points from your segmentation report are non-inclusive
- Segment size is determined by the “segment size” value set in Service Editor > General Properties
- During execution the segment size is passed automatically to the segment size prompt
In summary, you need 3 prompts specifically to make segmentation work. Segment start, segment end, and segment size. Your segmentation report should only return the starting point of each segment. Of course, the starting points are determined by the values in your segmentation attribute which is the same as your subscription ID. I hope this is more helpful then confusing. Comments are appreciated as always.