Re: random_page_cost vs ssd? - Mailing list pgsql-performance

From Grzegorz Jaśkiewicz
Subject Re: random_page_cost vs ssd?
Date
Msg-id 2f4958ff0903110837x21aa4c75m4473d053127c043d@mail.gmail.com
Whole thread Raw
In response to random_page_cost vs ssd?  (Jeff <threshar@torgo.978.org>)
Responses Re: random_page_cost vs ssd?  (Scott Carey <scott@richrelevance.com>)
List pgsql-performance
On Wed, Mar 11, 2009 at 1:46 PM, Jeff <threshar@torgo.978.org> wrote:
> I've got a couple x25-e's in production now and they are working like a
> champ.  (In fact, I've got another box being built with all x25s in it. its
> going to smoke!)
>
> Anyway, I was just reading another thread on here and that made me wonder
> about random_page_cost in the world of an ssd where a seek is basically
> free.  I haven't tested this yet (I can do that next week), but logically,
> in this scenario wouldn't lowering random_page_cost be ideal or would it not
> really matter in the grand scheme of things?

Just on a side note, random access on SSD is still more expensive than
sequential, because it is designed in banks.
If you don believe me, turn off any software/OS cache , and try random
access timing against seq reads.
This gap is just much much narrower.


--
GJ

pgsql-performance by date:

Previous
From: Jeff
Date:
Subject: random_page_cost vs ssd?
Next
From: Scott Carey
Date:
Subject: Re: random_page_cost vs ssd?