another DECIMAL problem

Hi all,

I'm trying to create an index on a composite key using a DECIMAL type
but PostgreSQL raises the following error:


CREATE TABLE header (       year                    decimal(4) NOT NULL,       number                  INTEGER  NOT
NULL,      date                    DATE     NOT NULL,       cod_client              CHAR(4)  NOT NULL,       CONSTRAINT
k_headerPRIMARY KEY (year,number)       );
 
NOTICE:  CREATE TABLE/PRIMARY KEY will create implicit index 'k_header'
for tabl
e 'header'
ERROR:  Can't find a default operator class for type 1700.

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PostgreSQL 6.5.0 on i586-pc-linux-gnulibc1, compiled by gcc 2.7.2.1

José