Merging extents to get fewer extents (defragmentation) is beneficial to customers who have a large number of extents in a partition and are likely to run into the partition page overflow problem.

On a subsequent scan, if a newly computed checksum is different from the previously generated checksum, the page is changing and is therefore not a good candidate for merging.

Merging the course directory and course detail pages (and Ajaxifying the underlying code) allows you to show course details without loading a new page.