To quickly know which databases are available on your system:
<?php
$cst = array(
'GEOIP_COUNTRY_EDITION' => GEOIP_COUNTRY_EDITION,
'GEOIP_REGION_EDITION_REV0' => GEOIP_REGION_EDITION_REV0,
'GEOIP_CITY_EDITION_REV0' => GEOIP_CITY_EDITION_REV0,
'GEOIP_ORG_EDITION' => GEOIP_ORG_EDITION,
'GEOIP_ISP_EDITION' => GEOIP_ISP_EDITION,
'GEOIP_CITY_EDITION_REV1' => GEOIP_CITY_EDITION_REV1,
'GEOIP_REGION_EDITION_REV1' => GEOIP_REGION_EDITION_REV1,
'GEOIP_PROXY_EDITION' => GEOIP_PROXY_EDITION,
'GEOIP_ASNUM_EDITION' => GEOIP_ASNUM_EDITION,
'GEOIP_NETSPEED_EDITION' => GEOIP_NETSPEED_EDITION,
'GEOIP_DOMAIN_EDITION' => GEOIP_DOMAIN_EDITION,
);
foreach ($cst as $k=>$v) {
echo $k.': '.geoip_db_filename($v).' '.(geoip_db_avail($v) ? 'Available':'').'<br>';
}
?>
The only drawback of the PECL extension with respect to a pure PHP implementation is that you cannot select yourself where the database is. So, if you get a new version of the database, you need to put in the standard place and you may need root access to do so.