FWD: latch contention

I wanted to open discussion on some of the info from onstat -g spi and what might alleviate contention for certain resources. Here is a list of latches which I have an interest in and my thoughts on what they might mean. --shmcb sh_lock From what I have read, I think this might be related to allocating space in the virtual part of shared memory for a session. If that is the case, it would make sense if one was doing a lot of light scans and light appends to have resource contention for this. The only thing I can think of to lessen contention would be to have less people doing light scans on this server at one time. --mtcb sleeping_lock I am guessing this might be due to requests to be put on the sleeping list for the thread control block. I have no clue what would cause this on a system that does not have many users. --pool po_lock, name = rsam Raw sequential access method? Thats just my guess. If I am doing alot of light scans and appends, and I am using raw disk, it would make sense for this to be used alot, any clue what my lesson contention for this resource? The only thing I can think of would be more CPUVP's(because they do the KAIO). If anyone has thoughts on these, I would love to hear them. Will