Why Doesn't Buffer Pagesize match System Pagesize?

We run Informix OnLine 7.12UC5 on a Sun Ultra 6000. Solaris reports a pagesize of 8k (for the sun4u Ultra SPARC, - - type "pagesize" on your Solaris system if you have a different chip) Informix seems to be dealing with a pagesize of 2k. ("onstat -b" says ".... 2048 buffer size"). Does this mean that every time the engine reads a buffer page, the system delivers 8k, and Informix ignores all but the first 2k? So that to read 200k, Informix performs 100 IO operations, instead of 25? If there are any Ultra users out there, please let me know what pagesize your version 7 Informix engine is using. I wonder if Informix has released a version for the Ultra platform that I don't have. Without wasting a lot of time, I'll just say that it took Informix 4 attempts to get us the Solaris 2.5.1 version that we are now running, and I am not yet comfortable that it perfectly matches our system. If the version we have is correct, why did Informix compile the engine with a pagesize that doesn't match the target platform? Am I missing something? (I realize that that parts of the engine are probably implemented with mmap instead of read and write, and that kaio is used on raw partitions - - none of that changes what the actual chip MMU and busses do. I mention this only to reduce stray replies.) Thanks for your help, Randy (I am not a list subscriber, so please reply to me directly. The list subscribers here wanted me to send the question. I will be happy to post a SUMMARY to the list.)