Re: SSD performance - Mailing list pgsql-performance

From Matthew Wakeling
Subject Re: SSD performance
Date
Msg-id alpine.DEB.1.10.0901231148140.4317@aragorn.flymine.org
Whole thread Raw
In response to Re: SSD performance  (Luke Lonergan <LLonergan@greenplum.com>)
List pgsql-performance
On Fri, 23 Jan 2009, Luke Lonergan wrote:
> Why not simply plug your server into a UPS and get 10-20x the
> performance using the same approach (with OS IO cache)?
>
> In fact, with the server it's more robust, as you don't have to transit
> several intervening physical devices to get to the RAM.
>
> If you want a file interface, declare a RAMDISK.
>
> Cheaper/faster/improved reliability.

I'm sure we have gone over that one before. With that method, your data is
at the mercy of the *entire system*. Any fault in any part of the computer
(hardware or software) will result in the loss of all your data. In
contrast, a RAM-based SSD is isolated from such failures, especially if it
backs up to another device on power fail. You can completely trash the
computer, remove the SSD and put it into another machine, and boot it up
as normal.

Computers break. Nothing is going to stop that from happening. Except VMS
maybe.

Not arguing that your method is faster though.

Matthew

--
 "Finger to spiritual emptiness underlying everything."
        -- How a foreign C manual referred to a "pointer to void."

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