Classes

The component core is split into 3 classes: pdoTools (general), pdoFetch (database), and pdoParser (templating).

They register on install so you can run them like this:

$pdoTools = $modx->getService('pdoTools');
$pdoFetch = $modx->getService('pdoFetch');
$pdoParser = $modx->getService('pdoParser');

pdoFetch extends pdoTools, so you don't need both. Use Fetch for database work, Tools otherwise.

You don't need to call the parser directly; it is enabled or disabled in MODX. pdoTools uses it for chunk processing anyway.