I have been too busy since getting back from vacation, thus no posts for a while. But I hope the waiting was worthwhile as I present you LatchProf, a tool for digging in to latch contention problems – using plain SQL and sqlplus!
As, I’m still busy, I make it short.
LatchProf is a script similar to WaitProf, only it samples latch holder statistics from V$LATCHHOLDER. As V$LATCHHOLDER contains a SID column (with session ID of a latch holder) it becomes possible to find who is hitting a latch the most (a way to prove that crappy monitoring tools which constantly scan through V$SQL DO cause library cache latch contention themselves).