LOAD — load a shared library file
LOAD 'filename'
   This command loads a shared library file into the PostgreSQL
   server's address space.  If the file has been loaded already,
   the command does nothing.  Shared library files that contain C functions
   are automatically loaded whenever one of their functions is called.
   Therefore, an explicit LOAD is usually only needed to
   load a library that modifies the server's behavior through “hooks”
   rather than providing a set of functions.
  
The library file name is typically given as just a bare file name, which is sought in the server's library search path (set by dynamic_library_path). Alternatively it can be given as a full path name. In either case the platform's standard shared library file name extension may be omitted. See Section 36.10.1 for more information on this topic.
   Non-superusers can only apply LOAD to library files
   located in $libdir/plugins/ — the specified
   filename must begin
   with exactly that string.  (It is the database administrator's
   responsibility to ensure that only “safe” libraries
   are installed there.)
  
   LOAD is a PostgreSQL
   extension.