Venu Anuganti Blog

Today I just happen to read May 2008 edition of Dr.Dobb’s Journal printed edition and the article “Kernel-mode Databases” written by Andrel and Alexander from McObject really excited me.

The basic principle of any database engine is its performance and scalability and success of any database in most part relays on these two concepts. To achieve this, operating system kernel plays a major role in the form of …

• resource allocation
• thread scheduling
• low-level hardware access
• network
• security

So, looks like eXtremeDB try to overcome from this by releasing kernel-mode database. The kernel mode package actually overrides most of the kernel access calls that database engine expects by replacing with optimized direct calls and exposing them to the top layer. And the run-time engine of eXtremeDB actually linked with the kernel mode to avoid any overhead from the RPC.

Interesting quotes: “Kernel-mode threads have direct access to kernel-mode databases; concurrent access is coordinated by the database run-time” “Applications performing computer security functions performed an order of magnitude faster”

It will be really nice if McObject can release benchmark results between regular kernel threads and the optimized one, along with conducting some more tests to prove the benefit from their kernel mode. Even though they found a solution for part of the common problems (kernel overhead, security, thread scheduling) but still there is a overhead from regular IO and exclusive lock time when doing the updates. Looks like some of their locks are using “Compare-and-swap“; but could not find much reference to where they were actually used within the code base.

After Microsoft released its beta version of “SQL Server Data Services“; I was more interested to know what kind of considerations were taken care in the design and architecture of SSDS in order to get performance, distribution of data and scalability as it is developed on top of SQL Server.

To my surprise, I noticed Microsoft is conducting the live event to answer some of these questions by following up Ryan Dunn blog; Today I also got the confirmation to attend the event and I look forward to get some of my general questions answered.

It will be interesting to see the pricing model of SSDS in the coming days, and might even attract if they make it FREE for initial customers and/or by setting the limit on the data usage by distributing it as part of OS. It will be really cool if they could also integrate some kind of access mechanism as part of the windows operating system itself to access/store the data.

I hope Microsoft will also change the name of SSDS to something else before the final release as Data Services is not catchy and does not sound right (check yet another post on the similar lines).