Re: parametric block size?

Hi,

On 2014-07-22 10:22:53 +0200, Fabien wrote:
> The default blocksize is currently 8k, which is not necessary optimal for
> all setup, especially with SSDs where the latency is much lower than HDD.

I don't think that really follows.

> There is a case for different values with significant impact on performance
> (up to a not-to-be-sneezed-at 10% on a pgbench run on SSD, see
> http://www.cybertec.at/postgresql-block-sizes-getting-started/), and ISTM
> that the ability to align PostgreSQL block size to the underlying FS/HW
> block size would be nice.

I don't think that benchmark is very meaningful. Way too small scale,
way to short runtime (there'll be barely any checkpoints, hot pruning,
vacuum at all).

> More advanced features, but with much more impact on the code, would be to
> be able to change the size at database/table level.

That'd be pretty horrible because the size of pages in shared_buffers
wouldn't be uniform anymore.

Greetings,

Andres Freund

-- Andres Freund                       http://www.2ndQuadrant.com/PostgreSQL Development, 24x7 Support, Training &
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