dbh connect

[Frank Newland]

Are there any  $dbh->connect  statements I can use to prevent the following
error message. 


"ORA-01555: snapshot too old:
rollback segment number 19
with name "R20" too small

I'm running a simple 'Where not exists' against an Oracle table of 4Million
records.

my current $dbh->connect reads as follows

$dbh = DBI->connect (
           "dbi:Oracle:$oracle_sid", $db_user, $db_password,
           {PrintError => 0, AutoCommit => 0}
            )  || die "Failed to connect "  ; 

Thanks,

Frank