I said: > This doesn't seem to quite square > with your explanation though --- surely the number should go to 8000 and > change? The man page for top says these numbers are in kilobytes ... > but if they were really measured in, say, 4K pages, then we'd be talking > about 26M of shared memory touched, which might be plausible when you > consider shared libraries.
Never mind --- further testing shows that top does report in kilobytes. I made a silly mistake in writing my test query that prevented it from using as many buffers as I expected. When I write something that really does use all 1000 buffers, SHARE goes to 10392, which is right about what you'd expect. So I think this mystery is solved. Back to chasing real bugs ... 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