Best way to import data in postgresl (not "COPY")

Hello,

I have a system that must each day import lots of data from another one.
Our system is in postgresql and we connect to the other via ODBC.

Currently we do something like :

SELECT ... FROM ODBC source
foreach row {
INSERT INTO postgresql
}

The problem is that this method is very slow...

More especially that for each row we do :
field1 = ...
field2 = ...
And then
$sql_insert = "INSERT ..." . field1 ....


Does someone has a better suggestion ?

Thanks a lot in advance !

Denis