Index on int8

Hello,

I just installed v6.4 and it works fine. The type int8 is now available
on Linux without need to use the contrib/int8.

But how can I make an index on int8-fields? Create index returns
create table l (i int8);
create index li on l using btree(i);

ERROR: Can't find a default operator class for type 20.

I just tried add an operator-class and included the 5 comparison
operators in pg_opclass, pg_amop but that seems not to be enough.

Some idea?

An other question: Is there some DECIMAL or fixed-point type of about 13
digits?

Kind regards,

Michael Contzen

Dohle Systemberatung
Germany