* Jim C. Nasby: > The problem is that it seems like there's never enough ability to clue > the OS in on what the application is trying to accomplish. For a long > time we didn't have a background writer, because the OS should be able > to flush things out on it's own before checkpoint. Now there's talk of a > background reader, because backends keep stalling on waiting on disk IO.
I've recently seen this on one of our test systems -- neither CPU nor disk I/O were maxed out. Have you considered using asynchronous I/O? Maybe it results in less complexity and fewer context switches than a background reader. ---------------------------(end of broadcast)--------------------------- TIP 9: In versions below 8.0, the planner will ignore your desire to choose an index scan if your joining column's datatypes do not match