As of postgresql 9.1 "standard_conforming_strings" is set to on
This will not work anymore
<?php
$copy_message = "1\t\\N\t300";
pg_copy_from($db, "message", $copy_message);
?>
result will be a "N" in that field. if the field allow text that is else it will fail to insert the post.
simple fix
<?php
$copy_message = "1\t\\NULL\t300";
pg_copy_from($db, "message", $copy_message, "\t","\\NULL");
?>