BUG #8199: row datatypes are not hashable

The following bug has been logged on the website:

Bug reference:      8199
Logged by:          Rafal Rzepecki
Email address:      divided.mind@gmail.com
PostgreSQL version: 9.2.4
Operating system:   Ubuntu 13.04
Description:        =


Row datatypes are currently not hashable, which makes it slower to use them
in a UNIQUEd query and impossible to use them in a recursive query (unless
using UNION ALL):

divide=3D# create type the_row as (mfg text, id text);
CREATE TYPE
divide=3D# with recursive rec(w, i) as (                                   =
   =

                                                           =

select '(pow,xyzzy)'::the_row, 3
union
select w, i-1 from rec where i > 0
) select * from rec;                =

ERROR:  could not implement recursive UNION
DETAIL:  All column datatypes must be hashable.