Re: Tuplesort merge pre-reading

On Fri, Sep 9, 2016 at 1:01 PM, Heikki Linnakangas <hlinnaka@iki.fi> wrote:
> I'm happy with what it looks like. We are in fact getting a more sequential
> access pattern with these patches, because we're not expanding the pre-read
> tuples into SortTuples. Keeping densely-packed blocks in memory, instead of
> SortTuples, allows caching more data overall.


Wow, this is really cool. We should do something like this for query
execution too.

I still didn't follow exactly why removing the prefetching allows more
sequential i/o. I thought the whole point of prefetching was to reduce
the random i/o from switching tapes.

-- 
greg