Restrictions on Spatial Indexes
A spatial index can be created only on a column of type geometry or geography.
Spatial indexes can be defined only on a table that has a clustered primary key. The maximum number of primary key columns on the table is 15.
The maximum size of index key records is 895 bytes. Larger sizes raise an error.
Primary key metadata cannot be changed while a spatial index is defined on a table.
Spatial Indexes cannot be specified on indexed views.
You can create up to 249 spatial indexes on any of the spatial columns in a supported table. Creating more than one spatial index on the same spatial column can be useful, for example, to index different tessellation parameters in a single column.
You can create only one spatial index at a time. For more information, see CREATE SPATIAL INDEX (Transact-SQL) or How to: Create a Spatial Index (SQL Server Management Studio).
An index build cannot make use of available process parallelism.