Hugo Kornelis continues a series on storage internals:
To understand spatial indexes, we first need to understand a process known as “tessellation”. This is a process where a shape is divided into smaller elements, that then can be recursively divided even further, to result in a list of cells with, for each, an attribute that indicates whether the object partially or fully covers that cell.
Read on to learn more about the concept, how SQL Server uses the idea of tessellation to convert shapes into a practical tabular form, and why it’s so valuable to have an index over this form.