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_NumGeometries
ST_NumGeometries returns the number of geometries in an input geometry.
Syntax
ST_NumGeometries(geom)
Arguments
- geom
-
A value of data type
GEOMETRY
or an expression that evaluates to aGEOMETRY
type.
Return type
INTEGER
representing the number of geometries in geom.
If geom is null, then null is returned.
If geom is a single empty geometry, then 0
is returned.
If geom is a single nonempty geometry, then 1
is returned.
If geom is a GEOMETRYCOLLECTION
or a MULTI
subtype,
then the number of geometries is returned.
Examples
The following SQL returns the number of geometries in the input multilinestring.
SELECT ST_NumGeometries(ST_GeomFromText('MULTILINESTRING((0 0,1 0,0 5),(3 4,13 26))'));
st_numgeometries
-------------
2