Re: For the ametures. (related to "Are we losing momentum?")

Matthew T. O'Connor wrote:

> ----- Original Message -----
> From: "Ben Clewett" <B.Clewett@roadrunner.uk.com>

>>Working with IDE drives on PC's,  you can double the performace of a DB
>>just by putting half the tables on a disk on another IDE chain.
> 
> 
> You can do this using symlinks, but you do have to shut down the postmaster
> before you play with the files directly.


I was hoping this was the case. :)
From my data/base directory, I have a tree structure of numbered files 
of no obvious structure.  As well as some smaller directories, 'global', 
'pg_xlog' and 'pg_clog'.

If I wanted to divide the postmaster read() calls evenly to files 
located over several physical disks, how would you suggest distributing 
the data-space?  Would it be as simple as putting each child directory 
in 'data/base' on a different physical disk in a round-robbin fasion 
using symbolic links:  Or is it more involved...

data/base/1 -> /dev/hda
data/base/2 -> /dev/hdb
data/base/3 -> /dev/hdc
data/base/4 -> /dev/hda
data/base/5 -> /dev/hdb
data/base/6 -> /dev/hdc (etc)

(I have made the assumption that the postmaster serves different 
connections in parallel, otherwise this would have little effect :)

Thanks,

Ben