It does show the whole "pieced together" statement upon ->execute ... what trace level are you using? what version of DBI?

Update: I see the complete statement using DBD::Pg and trace(2) .. but i don't see it w/this test snippet:

use strict;
use warnings;
use DBI;
my $dbh = DBI->connect("DBI:CSV:f_dir=/tmp");
$dbh->trace(2);
$dbh->do("CREATE TABLE a (id INTEGER, name CHAR(10))");
$dbh->do("INSERT INTO a (id, name) values (?,?)", {}, 1, 'one');
$dbh->selectall_arrayref("select * from a where id < ?",{},2);
my $sth = $dbh->prepare("select * from a where id < ?");
$sth->execute(2);
use Data::Dumper;
warn Dumper $sth->fetchall_arrayref();
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