HTTP Download with Postgresl Blob

Hi, I read blobs from a postgresql database, using native pg functions (not DB or MDB). Then I want to send this blob as a download which works fine using HTTP_Download's setData() method. Problem is, that sometimes these blobs can be up to 40MB which cause PHP to choke on the memory limit. I tried using setResource() but the pg LO resource, obtained by using pg_lo_open() is not a valid stream resource. Is there a solution here, or do I just need to up my php memory limit? I was wondering if I could use HTTP download together with pg_lo_read_all(). I'd like to send all the right headers using HTTP_Download and then send the data using pg_lo_read_all(). Is that possible? TIA Jeroen