Re: 10K vs 15k rpm for analytics

On Mar 2, 2010, at 1:36 PM, Francisco Reyes wrote:

> david(at)lang(dot)hm writes:
>
>> With sequential scans you may be better off with the large SATA drives as
>> they fit more data per track and so give great sequential read rates.
>
> I lean more towards SAS because of writes.
> One common thing we do is create temp tables.. so a typical pass may be:
> * sequential scan
> * create temp table with subset
> * do queries against subset+join to smaller tables.
>
> I figure the concurrent read/write would be faster on SAS than on SATA. I am
> trying to move to having an external enclosure (we have several not in use
> or about to become free) so I could separate the read and the write of the
> temp tables.
>

Concurrent Read/Write performance has far more to do with OS and Filesystem choice and tuning than what type of drive it is.

> Lastly, it is likely we are going to do horizontal partitioning (ie master
> all data in one machine, replicate and then change our code to read parts of
> data from different machine) and I think at that time the better drives will
> do better as we have more concurrent queries.
>
>
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