On Sat, Jul 26, 2014 at 1:37 PM, Fabien COELHO <coelho@cri.ensmp.fr> wrote:
>> And I don't see that as being warranted at this point. But further
>> benchmarks sound like a good idea.
>
> Yep. A 10% potential performance impact looks worth the investigation.
I wonder, though, whether this isn't using a crowbar where some finer
instrument is called for. If, for example, bigger heap blocks give
better performance because a bigger I/O size just plain works better,
well then that's interesting in its own right. But if a bigger or
smaller block size yields better results on index scans, the right
solution might be to change the internal page structure used by that
index. For example, I remember reading a paper a few years back where
the authors found that large page sizes were inefficient because you
had to do a linear scan of all the items on the page; so they added
some kind of btree-like structure within the page and got great
results. So the page size itself wasn't the fundamental issue; it had
more to do with what kind of page layout made sense at one page size
vs. another page size.
--
Robert Haas
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