CREATE ACCESS METHOD — define a new access method
CREATE ACCESS METHODnameTYPEaccess_method_typeHANDLERhandler_function
   CREATE ACCESS METHOD creates a new access method.
  
The access method name must be unique within the database.
Only superusers can define new access methods.
nameThe name of the access method to be created.
access_method_type
      This clause specifies the type of access method to define.
      Only TABLE and INDEX
      are supported at present.
     
handler_function
      handler_function is the
      name (possibly schema-qualified) of a previously registered function
      that represents the access method.  The handler function must be
      declared to take a single argument of type internal,
      and its return type depends on the type of access method;
      for TABLE access methods, it must
      be table_am_handler and for INDEX
      access methods, it must be index_am_handler.
      The C-level API that the handler function must implement varies
      depending on the type of access method. The table access method API
      is described in Chapter 63 and the index access method
      API is described in Chapter 64.
     
   Create an index access method heptree with
   handler function heptree_handler:
CREATE ACCESS METHOD heptree TYPE INDEX HANDLER heptree_handler;
   CREATE ACCESS METHOD is a
   PostgreSQL extension.