default operator (int8le?)

I have a field key that is int8;

create table arg ( key int8 );

create index ix_argkey on arg using hash (key) ;
/*ERROR:  Can't find a default operator class for type 20.*/

drop table arg;

I'm guessing that this is related to the dashed out entries for oprrest and oprjoin.

select oprname, oprcode, oprrest, oprjoin from pg_operator where oprname like '%<%';

oprname|oprcode        |oprrest |oprjoin
-------+---------------+--------+------------
<>     |int48ne        |neqsel  |neqjoinsel
<      |int48lt        |intltsel|intltjoinsel
<=     |int48le        |-       |-
<      |boollt         |intltsel|intltjoinsel
<>     |boolne         |neqsel  |neqjoinsel
<      |int2lt         |intltsel|intltjoinsel
<      |int4lt         |intltsel|intltjoinsel
<>     |int8ne         |neqsel  |neqjoinsel
<      |int8lt         |intltsel|intltjoinsel
<=     |int8le         |-       |-
<>     |int84ne        |neqsel  |neqjoinsel
<      |int84lt        |intltsel|intltjoinsel
<=     |int84le        |-       |-
<<     |poly_left      |intltsel|intltjoinsel

If there is a trick fix, tell me the details, otherwise I'm happy with just reporting the problem.

--
Peter Schäfer - mailto:schaefer@cys.de, schaefer@dfu.de
Motto of the 3D Designer: "I am a meshed potato, I can do the twist".