Re: [tlug] Making better use of SSDs?

[Satoshi Nagayasu <satoshi.nagayasu@example.com>]

Hi Kalin,

2012/05/28 18:55, Kalin KOZHUHAROV wrote:
> On Mon, May 28, 2012 at 6:15 PM,<satoshi.nagayasu@example.com>  wrote:
> > A few days ago, I just published a technical report that examine
> > SSD performance compared with HDD to execute DWH (or analytics)
> > workloads on PostgreSQL. SSD was used for its data directory.
> Will the report be available somewhere to read?

Unfortunately, it's written in Japanese only (for now).
It's considerable to translate into English though...

If you can read Japanese, you can purchase the report
from my web site.

http://www.uptime.jp/ja/resources/techdocs/2012/05/pgsql_dbt3_hdd_ssd/

> > According to the experiments, it's been determined that SSD is able to
> > improve the query performance extremely if it has massive random
> > acccess I/O operations. As a results, more than 20 times faster
> > performance has been observed with some workloads.
> Yep, that is to be expected, more or less. Actually the more random
> and more processes try to read a HDD, the better improvement you'll
> see with databases. 10-100 times is not uncommon.
> No idea what is the size of your tables, but have you tried to fit
> them in memory?

Not yet.
The database size was x5 larger than the physical memory
of the database server. I intended to generate lots of
I/O operations.

> It will be a good indication of how much wait for IO is there, better
> than measuring it.
> If you don't want to change anything, just mount a tmpfs and put the
> data directory there and `mount -o bind` it to the old place (when db
> is down).

It seems worth trying. Thanks.

Regards,
--
NAGAYASU Satoshi <satoshi.nagayasu@example.com>