Rows with VARCHAR columns can experience expansion when VARCHAR values are updated with a longer string. In the case where the row cannot fit in the existing page, the row migrates, and access to the row will traverse a pointer. This only happens on heaps (tables without clustered indexes). In cases where clustered indexes cannot be used, drop non-clustered indexes, build a clustered index to reorg pages and rows, drop the clustered index, then recreate non-clustered indexes.