Insert a xml file into a DB

Hi there, I've been trying to insert (and retrieve) a xml file into a postgres DB into a BLOB field, using some nice examples downloaded from the net, but they don't seem to work. Is there a "standard" way to do this? I read about a bytea data type and run some examples, but never understood how this data type works. When I retrieve the data, all I could see was a number. What should I do with this number? How can I use it to see the xml file content.? Thank you in advance.