Cursor fetch performance issue

We are migrating our Oracle warehouse to Postgres 9.

This function responds well:

pg=# select public.getMemberAdminPrevious_sp2(247815829, 1,'test.email@hotmail.com', 'email', 'test');
 getmemberadminprevious_sp2
----------------------------
 <unnamed portal 1>
(1 row)

Time: 7.549 ms

However, when testing, this fetch takes upwards of 38 minutes:

BEGIN;
select public.getMemberAdminPrevious_sp2(247815829, 1,'test.email@hotmail.com', 'email', 'test');
FETCH ALL IN "<unnamed portal 2>";

How can I diagnose any performance issues with the fetch in the cursor?

Thanks.
Tony