Description: ------------ It appears only when the Oracle database is on the same computer than PHP. When you install OCI like described by Oracle, you can no more connect to the local database using the tnsnames.ora eg : you cannot connect with $c1 = ocilogon("scott", "tiger", "mydatabase"); but it's OK with $c1 = ocilogon("scott", "tiger", "myserver/mydatabase"); With pear:db, you must use $dbh = DB::connect("oci8://scott:tiger@myserver/mydatabase"); But in the oci8.php file, the $dsn['database'] is ignored and the connection fails. So the right code is $connect_function = $persistent ? 'OCIPLogon' : 'OCILogon'; if ($dsn['hostspec']) { if ($dsn['database']) { $this->connection = @$connect_function($dsn['username'], $dsn['password'], $dsn['hostspec'].'/'.$dsn['database']); } else { $this->connection = @$connect_function($dsn['username'], $dsn['password'], $dsn['hostspec']); } } elseif ($dsn['username'] || $dsn['password']) { $this->connection = @$connect_function($dsn['username'], $dsn['password']); }