David Griffiths wrote:
>>>To be honest, the vast majority of database installations experience
>>>problems in performance caused by poor query and schema design,
>>>bad application logic or grossly underspecified hardware. A change in
>>>the number of files used to store the data is extremely unlikely
>>>to resolve these problems given all other variables in the environment
>>>What does everyone else think?
>>I fully agree with the part about performance and the number of
>High-end database systems perfer more files, as they can be spread across
>multiple (usually fast SCSI) disks. Most databases recommend logs be kept on
>seperate disks than database files.
>Changes in the number of files can resolve problems if the problems are the
>result of low disk IO and you have money to throw at the problem.
True, but this isn't always the case.
Let's look at the almighty InnoDB for instance. It happily uses multiple
files for the data dictionary (ibdata*) if
you tell it but, as far as I know, treats them like one big space, not
doing striping or anything fancy.
Additionally, if you have money to throw at the problem, you'd throw
money at RAID and LVM. To prove my point,
I pose the following question:
* Would all those that enjoy extending database files as needed due to
upgrading disks etc please raise their hands?
Please? Come on! I promise that I won't tell SCO where you live....
With RAID you get performance and additional reliability if you want it.
With LVM you get online growth of your
storage if you are geeky and/or rich enough.
Regarding logs being kept seperately, you will get no argument from me!
In fact, if you can keep your logs on a
HA cluster of NAS boxes, in a safe, covered in concrete, connected by
multiply-redundant fibre-channel links,
guarded by half the population of Wagga Wagga and plastered with images
from random links from the awful,
awful bowels of the internet I still reckon that you'd probably be able
to find a way to go one better with
Look at SQLBase - "Zero Administration" they reckon. Log files do not
exist seperately, they exist inside the
same file that holds everything else! Not good! You need to do a
"reorganise" every few weeks or things start
to...well..err...suck! Give me MySQL any day!