Re: seqential vs random io

David Parker wrote:
> I just got a question from one our QA guys who is configuring a RAID 10
> disk that is destined to hold a postgresql database. The disk
> configuration procedure is asking him if he wants to optimize for
> sequential or random access. My first thought is that random is what we
> would want, but then I started wondering if it's not that simple, and my
> knowledge of stuff at the hardware level is, well, limited.....
>
> If it were your QA guy, what would you tell him?
>
> - DAP

Random. Sequential is always pretty fast, it is random that hurts.

The only time I would say sequential is if you were planning on
streaming large files (like iso images) with low load.

But for a DB, even a sequential scan will probably not be that much data.

At least, that's my 2c.

John
=:->