MOnagals

Part 1: The NoSQL hoopla … What is NonsenSQL about it?

After not looking at it seriously for a long time, during the last few months, I have been paying closer attention to the NoSQL phenomenon. I have been amazed at the amount of hoopla associated with it and the “anything goes” attitude of a significant fraction of the people using and/or working on such systems. Of late, it has become fashionable to diss RDBMSs, and a significant chunk of the technologies that have been laboriously thought about and worked out over the last few decades. Some inconvenient/inadequate features of RDBMSs in certain contexts have been used as arguments to throw the baby with the bath water while coming up with alternatives. As some of us anticipated, many features which were initially considered unnecessary/undesirable, are now being retrofitted to the NoSQL systems, in many cases in ad hoc and simple-minded ways. 

Having worked in the database field for more than 3 decades with a fair amount of impact on the research and commercial sides of this field (see http://bit.ly/cmohan), it pains me to see the casual way in which some designs have been done and some supposedly new ideas get proposed/implemented. Not enough efforts are being made to relate these proposals to what has been done in the past and benefit from the lessons learnt in the context of RDBMSs. Not everything needs to be done differently just because it is supposedly a very different world now! 

As a senior citizen of the database community, I feel I need to say something on this and related topics. For a while, I have been irregular in expressing my opinions very vocally in public fora. Now, I have decided to use this blog to become somewhat more active :-)

Of course, I have to state the obvious: what I say in this blog are all my personal opinions and they don’t necessarily reflect the opinions of my employer of the last 30 years!

I did raise some heckles and asked some uncomfortable questions when my academic sibling Raghu Ramakrishnan gave what I strongly felt was a very one-sided keynote (“Cloud Data Serving: Key-Value Stores to DBMSs”) at VLDB 2009 in Lyon where he extolled the benefits of such systems without enough caveats around what he was saying. I felt the impressionable minds, who constituted a significant fraction of the huge audience, deserved to be exposed to the latter. 

As the General Chair, I listened to a number of related presentations at HPTS 2011 workshop in Asilomar (http://bit.ly/HPTSpr). More recently, I attended the Silicon Valley edition of the MongoDB annual conference (MongoSV - http://bit.ly/MDsv11) along with, believe it or not, 1200 other people. After listening to some of the detailed presentations, I decided to tweet my reactions. What follows are a subset of the tweets I authored during that event. They may be of interest to people who didn’t see them before or to those who didn’t jot them down for later use. 

• seemohan #mongoSV whole bunch of papers on indexing, locking, logging, recovery, storage management, shared disks, … http://t.co/Pmy608Xh 10:56 PM Dec 9th, 2011 from web
• seemohan #mongoSV Index locking and recovery so easy when high concurrency isn’t a goal! See what real systems have had to do http://t.co/6Ik17RPW 10:51 PM Dec 9th, 2011 from web
• seemohan @divyagrawal I feel like I am 35+ years younger listening to age old stuff being talked about here at #mongoSV :-) Wow! 10:50 PM Dec 9th, 2011 from web
• seemohan #mongoSV Slides of a tutorial on high performance transaction processing (covers ARIES recovery/locking/indexing) http://t.co/pslUql3T 10:50 PM Dec 9th, 2011 from web
• seemohan #mongoSV Some war stories from original days of RDBMSs might be of interest to #mongoDB people - SQL 25 year reunion http://t.co/zwFARTHM 8:47 PM Dec 9th, 2011 from web
• seemohan #mongoSV The main ARIES paper (ACM Trans on Database Sys) IBM Res Rep version at http://t.co/hcKMcZsJ - The Bible on recovery/locking! 8:43 PM Dec 9th, 2011 from web
• seemohan #mongoSV Since Lotus Notes is a doc store like MongoDB what how we added industrial strength to Notes maybe of interest http://t.co/eNAEEkdV 8:05 PM Dec 9th, 2011 from web
• seemohan #mongoSV May be people should look at my ARIES papers for what real DBMSs do http://t.co/WDdTYMdp http://t.co/Pmy608Xh http://t.co/jSl49cDz 7:16 PM Dec 9th, 2011 from web
• seemohan #mongoSV For the ARIES guy (ME!), getting indigestion with the following: Single writer process, single DB wide lock scope in MongoDB :-)))) 7:12 PM Dec 9th, 2011 from web
• seemohan #mongoSV For a 30 year DB guy@IBM with also PhD in DB, so much of the mongoDB internals look so basic :-((( Did these people read old stuff? 6:30 PM Dec 9th, 2011 from web
• seemohan #mongoSV 1100 attendees, 50 sessions; 10gen: 80 employees, offices in Bay Area, NYC, London, Dublin - Microsoft working with mongoDB!! 5:31 PM Dec 9th, 2011 from web

In future posts, I hope to elaborate more on some of the points I have made above.