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Suppose you want to process a medium-to-large spatial data set and determine which points intersect with which polygons. In that case, first create a spatial index using STV_Create_Index. A spatial index provides efficient access to the set of polygons.
Then, use the STV_Intersect scalar or transform function to identify which point-polygon pairs match.
Before performing a spatial join using one of the STV_Intersect functions, you must first run STV_Create_Index to create a database object that contains information about polygons. This object is called a spatial index of the set of polygons. The spatial index improves the time it takes for the STV_Intersect functions to access the polygon data.
Vertica creates spatial indexes in a global space. Thus, any user with access to the STV_*_Index functions can describe, rename, or drop indexes created by any other user.
Vertica provides functions that work with spatial indexes:
STV_Create_Index—Stores information about polygons in an index to improve performance.
STV_Describe_Index—Retrieves information about an index.
STV_Drop_Index—Deletes a spatial index.
STV_Refresh_Index—Refreshes a spatial index.
STV_Rename_Index—Renames a spatial index.