User's Guide and Reference

Spatial functions for SQL queries

This chapter lists the available functions that you can invoke when you query spatial data. Each function is described in a section that shows you the syntax, return type, and code examples. Some of the examples in this chapter include a CREATE TABLE statement in which one or more columns are defined as spatial columns.

The following considerations apply to spatial functions:

• The examples in this chapter are qualified with the library name db2gse. Instead of explicitly qualifying each spatial function and type with db2gse, you can set the function path to include db2gse.
• Before you can insert data into a spatial column:
  • You might need to increase the udf_mem_sz parameter. The suggested initial setting is 2048. If 2048 is inadequate, increase the udf_mem_sz parameter in increments of 256.
  • You must register it as a layer. For more information about registering a spatial column as a layer, see Defining spatial columns, registering them as layers, and enabling a geocoder to maintain them.