Extensions
Scalar Functions
```sql
-- HasZ for a 2D geometry
SELECT ST_HasZ(ST_GeomFromText('POINT(1 1)'));
----
false

-- HasZ for a 3DZ geometry
SELECT ST_HasZ(ST_GeomFromText('POINT Z(1 1 1)'));
----
true

-- HasZ for a 3DM geometry
SELECT ST_HasZ(ST_GeomFromText('POINT M(1 1 1)'));
----
false

-- HasZ for a 4D geometry
SELECT ST_HasZ(ST_GeomFromText('POINT ZM(1 1 1 1)'));
----
true
```  
----  
#### ST_Hilbert {#docs:extensions:spatial:functions::st_hilbert}