NoSQL
Discussion of NoSQL concepts, products, and vendors.
Project Cassandra — Facebook’s open sourced quasi-DBMS
Edit: I posted much fresher information about Cassandra in July, 2010.
Facebook has open-sourced Project Cassandra, an imitation of Google’s BigTable. Actual public information about Facebook’s Cassandra seems to reside in a few links that may be found on the Cassandra Project’s Google code page. All the discussion I’ve seen seems to be based solely on some slides from a SIGMOD presentation. In particular, Dare Obasanjo offers an excellent overview of Cassandra. To wit: Read more
| Categories: Cassandra, Cloud computing, Data models and architecture, Facebook, NoSQL | 11 Comments |
Amazon SimpleDB – when less is, supposedly, enough
I’ve posted several times about Amazon as an innovative, super-high-end user — doing transactional object caching with ObjectStore, building an inhouse less-than-DBMS called Dynamo, or just generally adopting a very DBMS2-like approach to data management. Now Amazon is bring the Dynamo idea to the public, via a SaaS offering called SimpleDB. (Hat tip to Tim Anderson.)
SimpleDB is obviously meant to be a data server for online applications. There are no joins, and queries don’t run over 5 seconds, so serious analytics are out of the question. Domains are limited to 10GB for now, so extreme media file serving also isn’t what’s intended; indeed, Amazon encourages one to use SimpleDB to store pointers to larger objects stored as files in Amazon S3.
On the other hand, if you think of SimpleDB as an OLTP DBMS, your head might explode. There’s no sense of transaction, no mechanisms to help with integrity, no way to do arithmetic, and indeed no assurance that writes will be immediately reflected in reads. Read more
| Categories: Amazon and its cloud, Cloud computing, Data models and architecture, NoSQL, OLTP, Software as a Service (SaaS), Theory and architecture | 6 Comments |
Amazon Dynamo — when primary key access is enough
Amazon has a very decentralized technical operation. But even the individual pieces have interestingly huge scale. Thus, various different things they’re doing are of interest.
They recently presented a research paper on a high-performance transactional system called Dynamo. (Hat tip to Dare Obasanjo.) A key point is the following:
There are many services on Amazon’s platform that only need primary-key access to a data store. For many services, such as those that provide best seller lists, shopping carts, customer preferences, session management, sales rank, and product catalog, the common pattern of using a relational database would lead to inefficiencies and limit scale and availability. Dynamo provides a simple primary-key only interface to meet the requirements of these applications.
Now, I don’t think too many organizations past Amazon are going to decide that they can’t afford the overhead of an RDBMS for such OLTP-like applications. But I do think it will become increasingly common to find other reasons to eschew traditional OLTP relational architectures. Maybe you’ll want the schema flexibility of XML. Or perhaps you’ll be happy with a fixed relational schema, but will want to optimize for analytic performance.
| Categories: Amazon and its cloud, Cloud computing, Data models and architecture, Database diversity, NoSQL, OLTP, Theory and architecture | 1 Comment |
Amazon’s version of DBMS2
Last year, I pointed out that Amazon has a highly diversified DBMS strategy. Now Mike Vizard has a great interview with Werner Vogel, Amazon’s CTO, where he unearths a lot more detail. And it turns out that Amazon has been a hardcore adopter of DBMS2, since long before DBMS2 was named.
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