Sorting esp. if your data has some kind of natural sort order can increase compression (in columnar stores), decrease index size (bitmap or fancy bitmap indexes

Sorting esp. if your data has some kind of natural sort order can increase compression (in columnar stores), decrease index size (bitmap or fancy bitmap indexes) or lower query execution time (data is cluster vs random read). Here's one paper: Sorting improves word-aligned bitmap indexes, http://arxiv.org/abs/0901.3751 http://arxiv.org/abs/0901.3751