The LO file descriptor
The LO file descriptor is an integer value that identifies an open smart large object.
An LO file descriptor is similar to the file descriptors
for operating-system files. It serves as an I/O handle to the data
of the smart large object in the server. The LO file descriptors start
with a seek position of 0. Use the LO file descriptor
in one of the library
functions that accepts LO file descriptors.