I recently ran into the mention of INT8 and, by association, SERIAL8 by Informix engineers and a recent redbook. I want to make a quick comment on that.

It is likely that some of the clients connecting to your Informix engine will run on a different server than the engine.  Enabling a remote server for Informix connections is a simple three step process of setting up some environment variables, installing the free Informix Connect product and creating a sqlhosts file.

Create INFORMIXDIR

We need to create an INFORMIXDIR to hold our Connect install.  This is very similar to what we did with the engine install, except I like to name the INFORMIXDIR /opt/informix-connect to instead of just /opt/informix.