Retreiving data from PostgreSQL

Interested in creating a snippet to retrieve data from a PostgreSQL application that is on the same server as my modx domain (actually a subdomain).

When I try to connect to it using standard php pg_connect I am getting a parse error from ModX:
Call to undefined function pg_connect() in /manager/includes/document.parser.class.inc.php(769)

Is there any way to make a connection to a PostgreSQL database directly from within Modx as a snippet to retrieve data?

Thanks.

You need to have the pgsql extension configured and compiled into your PHP deployment in order to use this extension’s functions.  Refer to http://php.net/pgsql and http://php.net/manual/en/pgsql.installation.php for more information.

Hmm, thought I did as I have another php app already accessing it.

Will check.