Re: Data Storage Issue (Basic Issue)

Lew wrote:
> Tom Anderson wrote:
>> Databases typically store their data in a file [1]. ...
>> [1] Okay, so seriously heavyweight ones use disk extents/partitions 
>> and bypass the filesystem; how much of a difference does that make?
> 
> Anecdotally, on a large-scale test, above five-to-one.

I doubt that.

There are obviously overhead in the file system, but 400%
overhead in writing to a pre allocated file isntead of a raw
partition does not make any sense.

(if the file needs to be extended during write, then it sounds
very plausible, but that is not a fair comparison)

My impression is that raw partitions was not preferred for
performance but to ensure that there were no file systems
cached not being flushed to the plates.

Arne