binary data types and streaming

Hi-

I'm looking for information about storing binary data in postgres.  I've
set up a few tests where in I stored bytea data, but I have a few other
questions and I'm wondering if postgres will meet my needs.  Just to
start off, here's a couple of questions:

    What are the differences between using the bytea type and the BLOB
type?

    Is there any type of streaming support built into postgres' binary
datatype handling?  For instance, can I specify a beginning offset for
the binary data that I want>


I didn't see a whole lot of information about this topic in the postgres
8.1 manual.  Can anyone point me to documentation on this subject or
refer me to a book?  Thanks,


Dave