1) How do I find out what exactly is consuming the CPU in a PL/pgSQL function? All I see is that the calls to merge_all() function take long time, and the CPU is high while this is going on.
I have used this to profile some functions, and it worked pretty well. Mostly I use it on a test box, but once ran it on the live, which was scary, but worked great.
That looks promising. Turned it on, waiting for when I can turn the server at the next "quiet time".
I have to say this turned out into a bit of a disappointment for this use case. It only measures total time spent in a call. So, it sends up operations that waited a lot on some lock. It's good, but it would be great if total_time was provided along with wait_time (and io_time may be as well, since I also see operations that just naturally have to fetch a lot of data)
