Hello,
Your boss is making a good choice to upgrade but I can't comment on the AIX move. We run on HP and have run on AIX but got off of it years ago.
You will not be able to upgrade from one O/S to the other. Your best bet will be to upgrade on HP to 9.4, unload your data (use HPL). Install the same 9.4 version (9.40.FC4 is latest) on the new AIX system. Recreate your DB on AIX system and reload with HPL. This is the very simple answer since I do not know the size of your DB, number of tables, type etc. By doing it this way if you can make use of the large chunk support you'll have it. You can't just upgrade and it be available. Don't forget the new SDK and RECOMPILE!
The only 2 things I can think of that you will not be able to do is use onstat -g sql if you are a user and not Informix. IBM claims they did this for security reason but then tell you the way around it is to allow your users to be in the Informix group. Please don't do that. The other is you can no longer install to a link but must specify the actual path. Not an issue just aggrevating.
You can just ftp your existing configuration file but I would not use it. Just like with any major upgrade it is best to use the generic config that comes with it and put all your changes in it. that way you do not miss any of the new parameters.
Here are a few of the new 9.4 features:
Buffer Cache mgmt - significantly changed for heavy OLTP environments.
Large Chunk Support - the old 2G limitation for IDS is gone! Max chunks is now 32,767, and each can be 4 Terabytes. Wow. This change also affects load/unload utilities. Database capacity is now 128 Petabytes.
Many changes to Replication (HDR & ER can be used together)
SQL changes
New Btree scanner to remove the single btree cleaner performance limitation.
Many changes to onstat and oncheck.
Major page header changes (that internals stuff).
Hope this helps a bit.
Regards,
DBAGirl