Bruce Momjian <bruce@momjian.us> writes:
> Jim C. Nasby wrote:
>> If we extended relations by more than one page at a time we'd probably
>> have a better shot at the blocks on disk being contiguous and all read
>> at the same time by the OS.
> Actually, there is evidence that adding only a single page to the end
> causes a lot of contention for that last page, and that adding a few
> might be better.
Evidence where? The code is designed so that the last page *isn't*
shared --- go read the comments in hio.c sometime.
regards, tom lane