Amazon Redshift will no longer support the creation of new Python UDFs starting November 1, 2025.
If you would like to use Python UDFs, create the UDFs prior to that date.
Existing Python UDFs will continue to function as normal. For more information, see the
blog post
ST_NumInteriorRings
ST_NumInteriorRings returns the number of rings in an input polygon geometry.
Syntax
ST_NumInteriorRings(geom)
Arguments
- geom
-
A value of data type
GEOMETRYor an expression that evaluates to aGEOMETRYtype.
Return type
INTEGER
If geom is null, then null is returned.
If geom is not a polygon, then null is returned.
Examples
The following SQL returns the number of interior rings in the input polygon.
SELECT ST_NumInteriorRings(ST_GeomFromText('POLYGON((0 0,100 0,100 100,0 100,0 0),(1 1,1 5,5 1,1 1),(7 7,7 8,8 7,7 7))'));
st_numinteriorrings
-------------
2
