geometry_dump
Name
geometry_dump — A composite type used to describe the parts of complex geometry.
Description
geometry_dump
is a
composite data type
containing the fields:

geom
 a geometry representing a component of the dumped geometry. The geometry type depends on the originating function. 
path[]
 an integer array that defines the navigation path within the dumped geometry to thegeom
component. The path array is 1based (i.e.path[1]
is the first element.)
It is used by the
ST_Dump*
family of functions as an output type to explode a complex geometry into its
constituent parts.