windows allows one to partition in software, I think included in the
base OS. Can someone say if linux does or not (or at least a particular
version of linux). I do agree that hardware can do a more efficient
job than software.
I am not sure how expensive a RAID controller is to anyone who actually
needs multiple disks for performance of their app, I know my < $500
personal home machine came with it.
I believe Derby gives the OS plenty of opportunity to do parallel I/O
if there are multiple users in the database. Every thread can possibly
be doing I/O at a single time. There may be room to improve in the case
of checkpoint, but not sure how important that is.
I agree that single user Derby does not do parallel.
Øystein Grøvlen wrote:
"MM" == Mike Matrigali <[EMAIL PROTECTED]> writes:
MM> Yes this is probably incorrect in a number of places. There currently
MM> is only one segment. The segment number was added in the beginning so
MM> that if we ever had to do data partitioning ourselves we had a chance
MM> to
MM> add it without an ugly upgrade. But as you are seeing over time some
MM> hard coding has happened and if we ever really want another segment it
MM> will have to be cleaned up.
MM> My opinion is that the OS can do better data partitioning then we can so
MM> I don't think it is very useful to add that feature.
I agree that the OS often can do a better job with data partitioning
but that often requires expensive storage systems (e.g., RAID).
I think that many applications would perform better if it was possible
to put tables and indexes on different disks.
Also, Derby does not give the OS much opportunity to optimize IO as
long as it does not allow parallel disk accesses to a table.
