Spatial grid indexes
Indexes improve application query performance, especially when the queried table or tables contain many rows. If you create appropriate indexes that the query optimizer chooses to run your query, you can greatly reduce the number of rows to process.
IBM® Spatial Support for Db2 for z/OS® provides a grid index that is optimized for two dimensional data. The index is created on the X and Y dimensions of a geometry.
The following aspects
of a
grid index are helpful to understand:
- The generation of the index
- The use of spatial functions in a query
- How a query uses a spatial grid index