Geospatial Functions

The following topics describe the Vertica geospatial functions.

Function-Naming Conventions

The geospatial functions use the following naming conventions:

  • The ST_<function_name> functions are compliant with the latest Open Geospatial Consortium standard OGC SFA-SQL version 1.2.1 (reference. number is OGC 06-104r4, date: 2010-08-04). Currently, some ST_<function_name> functions may not support all data types. Each function page contains details about the supported data types.

Some functions, such as ST_GeomFromText, are based on previous versions of the standard.

  • The STV_<function_name> functions are unique to Vertica and not compliant with OGC standards. Each function page explains its functionality in detail.

Verifying Spatial Objects Validity

Many spatial functions do not verify the validity of the parameters. If you pass an invalid spatial object to an ST_ or STV_ function, the function may return an error or produce incorrect results.

To avoid this issue, Micro Focus recommends that you first run ST_IsValid on all spatial objects to verify their validity. If your object is not valid, run STV_IsValidReason to get information about the location of the invalidity.

If you pass a valid polygon to STV_IsValidReason, it returns NULL.

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