Re: [HACKERS] A Better External Sort?

On E, 2005-10-03 at 14:16 -0700, Josh Berkus wrote:
> Jeff,
>
> > > Nope, LOTS of testing, at OSDL, GreenPlum and Sun. For comparison, A
> > > Big-Name Proprietary Database doesn't get much more than that either.
> >
> > I find this claim very suspicious. I get single-threaded reads in
> > excess of 1GB/sec with XFS and > 250MB/sec with ext3.
>
> Database reads? Or raw FS reads? It's not the same thing.

Just FYI, I run a count(*) on a 15.6GB table on a lightly loaded db and
it run in 163 sec. (Dual opteron 2.6GHz, 6GB RAM, 6 x 74GB 15k disks in
RAID10, reiserfs). A little less than 100MB sec.

After this I ran count(*) over a 2.4GB file from another tablespace on
another device (4x142GB 10k disks in RAID10) and it run 22.5 sec on
first run and 12.5 on second.

db=# show shared_buffers ;
shared_buffers
----------------
196608
(1 row)

db=# select version();
version
--------------------------------------------------------------------------------------------
PostgreSQL 8.0.3 on x86_64-pc-linux-gnu, compiled by GCC cc (GCC) 3.3.6
(Debian 1:3.3.6-7)
(1 row)

--
Hannu Krosing <hannu(at)skype(dot)net>