O quarto link no google depois de pesquisar suas perguntas exatas trouxe o seguinte link:http://me2learn.wordpress.com/2008/10/18/connect-php-with-oracle-database/
<?php
$db = "(DESCRIPTION=(ADDRESS_LIST = (ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.1.34)(PORT = 1521)))(CONNECT_DATA=(SID=orcl)))" ;
if($c = OCILogon("system", "your database password", $db))
{
echo "Successfully connected to Oracle.\n";
OCILogoff($c);
}
else
{
$err = OCIError();
echo "Connection failed." . $err[text];
}
?>
