On 6/10/11 10:17 AM, Piumi Nanayakkara wrote:
Hi,
Thank you very much for your responses.
Our tentative plan is to change currently available optimization
techniques in relation to seek time/rotational latency which comes
with the normal magnetic disk,but can be avoided in solid state memory
device. Initially we are focusing on the optimization of Join
operation in Apache Derby. We thought of first comparing the
performance in two modes of devices with existing algorithms ( i.e.
Nested Loop Join and Hash Join) & existing join order and then to
modify them to utilize the benefits of solid state devices.
we highly appreciate any feedback on this or any suggestions of an
alternative approach that can be taken.
This sounds like a promising piece of research. It will be interesting
to see if you can map the differences between solid-state and
conventional disks onto the Cost Model variables in StoreCostController.
Keep us posted as your research proceeds. Based on your findings, we may
need to expand the existing Cost Model.
Thanks,
-Rick
Best Regards,
Piumi Nanayakkara
On Fri, Jun 10, 2011 at 7:37 PM, Rick Hillegas
<[email protected] <mailto:[email protected]>> wrote:
On 6/10/11 1:07 AM, Piumi Nanayakkara wrote:
Hi all,
For a research purpose I'm considering $subject when database
is stored in a solid state device.Can some one please clarify
me the packages/classes that i should study/modify for this
purpose.
Thank You!
Best Regards,
Piumi Nanayakkara
Hi Piumi,
Probably what is most relevant is the Cost Model for these
devices. Derby ships with a hard-coded Cost Model for heap and
index files. That Cost Model was tuned many years ago and probably
doesn't capture the actual performance of modern disks. I was not
part of the effort to tune that Cost Model so I can't give you a
lot of detail here.
If you want to tweak the Cost Model to better reflect the
performance of solid state disks, I recommend that you study the
org.apache.derby.iapi.store.access.StoreCostController interface
and its implementations. Unfortunately, I am not aware of any
tools which will help you create an implementation which is tuned
to the behavior of a particular disk. You may develop such a tool
as you pursue your research. If so, I encourage you to donate that
tool back to the community. I'm sure it will be useful to other
researchers and developers.
Perhaps you will get more detailed advice from someone who was
closer to the original effort which tuned the current Cost Model.
Sounds like an interesting project. Good luck!
Cheers,
-Rick
