Re: full_page_writes on SSD?

On 11/24/2015 10:48 AM, Marcin Mańk wrote:
> I saw this:
> http://blog.pgaddict.com/posts/postgresql-on-ssd-4kb-or-8kB-pages
>
> It made me wonder: if SSDs have 4kB/8kB sectors, and we'd make the
> Postgres page size equal to the SSD page size, do we still need
> full_page_writes?


an SSD's actual write block is much much larger than that.    they
emulate 512 or 4k sectors, but they are not actually written in sector
order, rather new writes are accumulated in a buffer on the drive, then
written out to a whole block, and a sector mapping table is maintained
by the drive.

--
john r pierce, recycling bits in santa cruz