Similar to a clustered index on a table, both horizontal and vertical partitioning are non-redundant, ., they incur little or no storage overhead. Also, in the same way that only one clustering can be chosen for a table, only one partitioning can be chosen for a table. This makes partitioning particularly attractive in storage constrained or update intensive environments. Commercial systems today support hash and/or range horizontal partitioning, and in some cases hybrid schemes as well. Horizontal partitioning can be useful for speeding up joins, particularly when each of the joining tables are partitioned identically (known as a .
