Archive for December, 2009

The “NoSQL” dispute: A performance argument

December 10, 2009 1 comment

NoSQL is a database movement that began in early to mid 2009 and which promotes non-relational data stores that do not need a fixed schema, and that usually avoid join operations. From [1]:

Next Generation Databases mostly address some of the points: being non-relational, distributed, open-source and horizontal scalable. The movement began early 2009 and is growing rapidly. Often more characteristics apply as: schema-free, replication support, easy API, eventually consistency, and more. So the misleading term “nosql” (some call it “not only sql”) should be seen as an alias to something like the definition above …

I just read a very insightful article from Michael Stonebraker [2], one of the pioneers of modern database theory and Relational Database Management Systems (RDBMS) and “father” of systems like Ingres and Postgres [3, 4]: ‘The “NoSQL” Discussion has Nothing to Do With SQL‘ [5]. In this article, published in the blog of the Communications of the ACM, Dr. Stonebraker responds to some of the arguments from the supporters of the NoSQL movement. There are two possible reasons to move away from structured Relational Database Management Systems and adopt an alternate DBMS technology: performance and flexibility:

The performance argument goes something like the following. I started with MySQL for my data storage needs and over time found performance to be inadequate. My options were: … 2. Abandon MySQL and pay big licensing fees for an enterprise SQL DBMS or move to something other than a SQL DBMS.

The flexibility argument goes something like the following. My data does not conform to a rigid relational schema. Hence, I can’t be bound by the structure of a RDBMS and need something more flexible. ….

Focusing on the performance argument, he explains what is more or less a common knowledge in the database community: The major performance burden of modern RDBMS  comes from all those extra features like transaction possessing (especially insuring the ACID properties), logging, etc and not from the core engine for executing an SQL query:

… However, the net-net is that the single-node performance of a NoSQL, disk-based, non-ACID, multithreaded system is limited to be a modest factor faster than a well-designed stored-procedure SQL OLTP engine. In essence, ACID transactions are jettisoned for a modest performance boost, and this performance boost has nothing to do with SQL.

In summary, blinding performance depends on removing overhead. Such overhead has nothing to do with SQL, but instead revolves around traditional implementations of ACID transactions, multi-threading, and disk management. To go wildly faster, one must remove all four sources of overhead, discussed above. This is possible in either a SQL context or some other context. …

I believe that anyone interested in the inner workings of modern RDBMS should read this short post from Dr. Stonebraker and continue with a very interesting paper from Harizopoulos, “OLTP through the looking glass, and what we found there” [6]. I am getting tired of discussing with people outside the database community who after writing a couple of SQL queries think that they know all about modern RDBMS and insist that the MySQL’s MYISAM engine is the best engine out there just because it is fast(er) or question my motives when I consult them that a “Lite SQL” (no reference to any real product)  solution is just not enough..

PS. Dr. Stonebraker is not just an exceptional database researcher, but a visionary whose ideas have shaped the modern Database landscape. A short abstract from an article in SIGMOD Record when he received the IEEE John von Neumann Medal [7]:

… The relational data model and its associated benefits of “data independence” and “non-procedural access” were first invented by Tedd Codd. However, more than any other individual, Mike is responsible for making Codd’s vision of independence a reality through the architectures and algorithms embodied in the series of open-source prototypes and commercial systems that he has initiated and led. While many others have certainly made important contributions to the field, no one else comes close to his continuous sequence of landmark innovations over a period of almost 30 years.

… Mike has been the primary driving force behind major shifts in the research agenda of the database community, including two occasions where he launched entire new directions for the field to follow (the implementation of relational systems and object-relational systems).

Categories: Databases Tags: ,

Preacquired Account Marketing

December 3, 2009 Leave a comment

Tens of millions of consumers have fallen prey to “free” trial offers and membership clubs offered by preacquired account marketers. These companies insert themselves into your everyday transactions, hoping to trick you into letting them charge your account. In simple words, Preacquired Account Marketing can be defined as [1]:

… The practice at issue is called post-transaction marketing, which involves the presentation of offers during the online checkout process. When done to deceive, these offers typically appear to be a required part of the checkout process, in order to trick consumers into accepting charges for unwanted products or services.

A particularly pernicious form of post-transaction marketing is known as “preacquired account marketing,” a process by which the third-party marketer acquires a customer’s credit card information from the online merchant where the customer is making a purchase.

Using this tactic, the third-party marketer only needs an e-mail address or a click as purchase authorization. The retailer, in effect, sells the customers’ credit card information because the retailer, as a partner, will get a cut of whatever extra charge the customer can be duped or pushed into accepting. …

As Michael Arrington explains in TechCrunch [2]:

… Background: hundreds of well known ecommerce companies add post transaction marketing offers to consumers immediately after something is purchased on the site. Consumers are usually offered cash back if they just hit a confirmation button. But when they do, their credit card information is automatically passed through to a marketing company that signs them up for a credit card subscription to a package of useless services. The “rebate” is rarely paid. …

What shocked me was the report from the USA Senate hearing some weeks ago, which focused on the controversial marketing companies that allegedly dupe consumers into paying monthly fees to join online loyalty programs [3]:

… Vertrue, Webloyalty, and Affinion generated more than $1.4 billion by “misleading” Web shoppers, said members of the U.S. Senate Committee on Commerce, Science and Transportation, which called the hearing. Lawmakers saved their harshest rebuke for Web retailers that accepted big money–a combined sum of $792 million–to share their customers’ credit-card information with the marketers. …

… Many of those who complained say they don’t fear the ad because they aren’t being asked to turn over credit-card information, according to the Senate report. But buried in the ad’s fine print is notification that by entering their e-mail address, the shopper is agreeing to join a loyalty program and allowing the store to authorize marketers to charge their card each month, between $9 and $12. …

Fraud, even of this magnitude, is a commonplace in the internet. That kind of scams rely on the fact that most consumers usually don’t notice 10-20$ charges in their monthly credit card statements. So, why bother? If you check the list of companies that are working with Affinion, Vertrue, and Webloyalty, you’ll find some highly reputable web sites that I would never think that they could be part of such a scam: Expedia,, US Airways,,, etc…

… Retailers doing business with the companies are also aware that customers are likely to be angered once they notice the charges but do it because they are paid big bucks. has pocketed $70 million from partnering with all three companies, according to the report. The government says that 19 retailers have made more than $10 million through the partnerships with e-loyalty programs, while 88 retailers have made more than $1 million ….

I have used Expedia and in the past and, even if they are not guilty, I’ll think twice before I’ll use them again. A huge reputation hit for such businesses (in the end, they are not just a fast growing gaming company [4], so they should be more careful), but a good lesson to learn for web 2.0 startups.. Unfortunately, electronic transactions are still defined and dealt through a ‘lighter’ moral viewpoint from many companies. I am sure that, for example, a traditional hotel booking company would risk less its reputation through that kind of deals. I believe that the transfer of credit card data in post-transaction offers must be restricted by law, and improved disclosure requirements and easier charge reversal must be regulated.

Categories: Business, web Tags: ,