H3_Boundary - Amazon Redshift
SyntaxArgumentsReturn typeExamples

H3_Boundary

H3_Boundary returns the boundary of an H3 cell ID from an input index. For information about H3 indexing, see H3.

Syntax

H3_Boundary(index)

Arguments

index

A value of data type BIGINT or VARCHAR that represents the index of an H3 cell. Or, an expression that evaluates to one of these data types.

Return type

POLYGON – represents the polygon with spatial reference system identifier (SRID) of 0.

If index is not valid, then an error is returned.

Examples

The following SQL inputs a VARCHAR that represents the index of an H3 cell, and returns a POLYGON with SRID 0 that represents the boundary of the input H3 cell. The output of H3_Boundary is input to ST_AwEWKT to display in extended well-known text (EWKT) representation.

SELECT ST_AsEWKT(H3_Boundary('8025fffffffffff'));

 st_asewkt
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
 POLYGON((87.7729641223953 52.6542030078627,86.7082098104731 40.3127667561966,98.2285042557705 33.6210697806835,110.694610548823 37.163896485796,116.212895637138 47.3094513028131,106.40349563788 56.210610737585,87.7729641223953 52.6542030078627))

The following SQL inputs a BIGINT that represents the index of an H3 cell, and returns a POLYGON with SRID 0 that represents the boundary of the input H3 cell. The output of H3_Boundary is input to ST_AwEWKT to display in extended well-known text (EWKT) representation.

SELECT ST_AsEWKT(H3_Boundary(577129255373111295)); 

 st_asewkt
-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
POLYGON((87.7729641223953 52.6542030078627,86.7082098104731 40.3127667561966,98.2285042557705 33.6210697806835,110.694610548823 37.163896485796,116.212895637138 47.3094513028131,106.40349563788 56.210610737585,87.7729641223953 52.6542030078627))