Sebastiao Pereira is a mad lad and I love it:
Is it possible to have the DBSCAN algorithm in SQL Server without the use of external tools? If so, can you please provide a working example?
DBSCAN is a neat algorithm for clustering and it is reasonably popular in the literature. I cannot imagine that it would perform well at all in SQL Server on a large dataset, though in fairness, I did try out the Mail_Customers example Sebastiao noted. This dataset includes 196 rows after you eliminate four duplicate combinations of annual income and spending score, and the procedure returned in less than a second. Now, getting the execution plan for this took a while, but it was neat to see this working.