Re: WAL prefetch

On Sat, Jun 16, 2018 at 3:41 PM, Andres Freund <andres@anarazel.de> wrote:
>> The posix_fadvise approach is not perfect, no doubt about that. But it
>> works pretty well for bitmap heap scans, and it's about 13249x better
>> (rough estimate) than the current solution (no prefetching).
>
> Sure, but investing in an architecture we know might not live long also
> has it's cost. Especially if it's not that complicated to do better.

My guesses are:

- Using OS prefetching is a very small patch.
- Prefetching into shared buffers is a much bigger patch.
- It'll be five years before we have direct I/O.

-- 
Robert Haas
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