Invalid memory alloc request size

Hi,

I'm using PostgreSQL 8.1.4 on a Linux 2.6.8-2-686-smp machine, 2 Go
memory. I have a strange error "invalid memory alloc request size",
when I perform the following query:

=> select * from player where lower(username) = 'wario';
ERROR: invalid memory alloc request size 1918988375

where player contains a bit more than 1 million records, username is a
character varying(255) not null.

I have strictly no idea about what goes wrong here. Whatever operation
I try to apply on the column username's value (lower, upper, length)
raises such an error.

I searched for some similar cases in the pgsql-sql archive but nothing
really similar. Any idea?

Regards,

P.S.: I don't have this problem on other tables containing less data.

--
Daniel CAUNE
Ubisoft Online Technology
(514) 490 2040 ext. 3613