One of the coolest features SQL Server 2008 has to offer is the new data type called hierarchyid (or SqlHierarchyId in the CLR). As you can begin to imagine this data type addresses a common issue when dealing with hierarchical data. You’ve probably been confronted with a scenario in witch you needed to data tree of some sort, and you’ve probably struggled with joins, recursive operations, and other strategies in the past. With this new type you can implement tree structures with ease, making use of the best indexing strategy. This article aims to explain what this data type is,...