ST_IsCollection
Name
   ST_IsCollection — Returns
   
    TRUE
   
   if the argument is a
                  collection (
   
    MULTI*
   
   ,
   
    GEOMETRYCOLLECTION
   
   , ...)
  
Synopsis
    
     boolean
     
      ST_IsCollection
     
     (
    
    geometry
    
     g
    
    
     )
    
    ;
   
Description
   Returns
   
    TRUE
   
   if the geometry type of
                  the argument is either:
  
- 
     
GEOMETRYCOLLECTION
 - 
     
MULTI{POINT,POLYGON,LINESTRING,CURVE,SURFACE}
 - 
     
COMPOUNDCURVE
 
       
      | 
     |
| 
       
       This function analyzes the type of the geometry. This means
                    that it will return
         | 
    
   
    
   
   This function supports 3d and will not drop the z-index.
  
   
    
   
   This method supports Circular Strings and Curves
  
Examples
postgis=# SELECT ST_IsCollection('LINESTRING(0 0, 1 1)'::geometry);
 st_iscollection
-------------
 f
(1 row)
postgis=# SELECT ST_IsCollection('MULTIPOINT EMPTY'::geometry);
 st_iscollection
-------------
 t
(1 row)
postgis=# SELECT ST_IsCollection('MULTIPOINT((0 0))'::geometry);
 st_iscollection
-------------
 t
(1 row)
postgis=# SELECT ST_IsCollection('MULTIPOINT((0 0), (42 42))'::geometry);
 st_iscollection
-------------
 t
(1 row)
postgis=# SELECT ST_IsCollection('GEOMETRYCOLLECTION(POINT(0 0))'::geometry);
 st_iscollection
-------------
 t
(1 row)