Re: Huge Data sets, simple queries

["Luke Lonergan" <llonergan(at)greenplum(dot)com>]

PFC,

On 1/31/06 3:11 PM, "PFC" <lists(at)peufeu(dot)com> wrote:

>> ... Prove it.
>> 
> 
> (I have a software RAID1 on this desktop machine)
> 
> It's a lot faster than a single disk for random reads when more than 1
> thread hits the disk, because it distributes reads to both disks. Thus,
> applications start faster, and the machine is more reactive even when the
> disk is thrashing. Cron starting a "updatedb" is less painful. It's cool
> for desktop use (and of course it's more reliable).

Exactly - improved your random seeks.

> However large reads (dd-style) are just the same speed as 1 drive. I
> guess you'd need a humongous readahead in order to read from both disks.

Nope - won't help.

- Luke