Manfred Spraul <[EMAIL PROTECTED]> writes: > I've noticed that postgres strace output contains long groups of > setitimer/semop/setitimer. > Just FYI: semtimedop is a special syscalls that implements a semop with > a timeout. It was added just for the purpose of avoiding the setitimer > calls. > I know that it's supported by Solaris and recent Linux versions, I'm not > sure about other operating systems.
I am ;-). We could not rely on using it. > Has anyone tried to use it? It would require a fairly messy crossing of platform-dependent with platform-independent code. Can we see some proof that there's a useful speedup possible before we think about this? AFAIK, semops are not done unless we actually have to yield the processor, so saving a syscall or two in that path doesn't sound like a big win. I'd be more interested in asking why you're seeing long series of semops in the first place. regards, tom lane ---------------------------(end of broadcast)--------------------------- TIP 9: the planner will ignore your desire to choose an index scan if your joining column's datatypes do not match