Data models and architecture
Discussion of issues in data modeling, and whether databases should be consolidated or loosely coupled. Related subjects include:
Social network analysis, aka relationship analytics
A number of applications lend themselves to graph-oriented analytics, including:
- Finding bad guys (national intelligence)
- Finding bad guys (anti-fraud)
- Data mining the social graph (e.g., for advertising optimization on social networks, or to identify influencers)
There are plenty more graph-oriented applications, of course, such as the identification of biochemical pathways. But I want to focus for now on ones like those on my list. My key points are:
- There are Big Data problems that lend themselves to graphical data models.
- So far as I can tell, the database management community isn’t doing enough to address them. (If I’m wrong about that, please tell me. I plan to arrive in Lyon for VLDB/XLDB Wednesday of next week, and of course I can always be reached by email.)
Here’s what I mean. Read more
| Categories: Analytic technologies, Cogito and 7 Degrees, Data models and architecture, Data types, RDF and graphs, Theory and architecture | 21 Comments |
NoSQL?
Eric Lai emailed today to ask what I thought about the NoSQL folks, and especially whether I thought their ideas were useful for enterprises in general, as opposed to just Web 2.0 companies. That was the first I heard of NoSQL, which seems to be a community discussing SQL alternatives popular among the cloud/big-web-company set, such as BigTable, Hadoop, Cassandra and so on. My short answers are:
- In most cases, no.
- Most of these technologies are designed for simple, high-volume OLTP (OnLine Transaction Processing.) Most large enterprises have an established way of doing OLTP, probably via relational database management systems. Why change?
- MapReduce is an exception, in that it’s designed for analytics. MapReduce may be useful for enterprises. But where it is, it probably should be integrated into an analytic DBMS.
- There’s one big countervailing factor to all these generalities — schema flexibility.
As for the longer form, let me start by noting that there are two main kinds of reason for not liking SQL. Read more
Schema flexibility and XML data management
Conor O’Mahony, marketing manager for IBM’s DB2 pureXML, talks a lot about one of my favorite hobbyhorses — schema flexibility — as a reason to use an XML data model. In a number of industries he sees use cases based around ongoing change in the information being managed:
- Tax authorities change their rules and forms every year, but don’t want to do total rewrites of their electronic submission and processing software.
- The financial services industry keeps inventing new products, which don’t just have different terms and conditions, but may also have different kinds of terms and conditions.
- The same, to some extent, goes for the travel industry, which also keeps adding different kinds of offers and destinations.
- The energy industry keeps adding new kinds of highly complex equipment it has to manage.
Conor also thinks market evidence shows that XML’s schema flexibility is important for data interchange. Read more
| Categories: Data models and architecture, EAI, EII, ETL, ELT, ETLT, IBM and DB2, pureXML, Structured documents | 3 Comments |
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 |
ScaleDB presents The Revenge of the Pointer
The MySQL user conference is upon us, and hence so are MySQL-related product announcements, including storage engines. One such is Kickfire. ScaleDB — smaller and earlier-stage — is another.
In a nutshell, ScaleDB’s proposition is:
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Innovative approach to indexing relational DBMS, providing performance advantages.
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Shared-everything scale-up that ScaleDB believes will leapfrog the MySQL engine competition already in Release 1. (In my opinion, this is the least plausible part of the ScaleDB story.)
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State-of-the-art me-too facilities for locking, logging, replication/fail-over, etc., also already in Release 1.
Like many software companies with non-US roots, ScaleDB seems to have started with a single custom project, using a Patricia trie indexing system. Then they decided Patricia tries might be really useful for relational OLTP as well. The ScaleDB team now features four developers, plus half-time or so “Chief Architect” involvement from Vern Watts. Watts seems to pretty much have been Mr. IMS for the past four decades, and thus surely knows a whole lot about pointer-based database management systems; presumably, he’s responsible for the generic DBMS design features that are being added to the innovative indexing scheme. On ScaleDB’s advisory board is PeopleSoft veteran Rick Berquist, about whom I’ve had fond thoughts ever since he talked me into focusing on consulting as the core of my business.*
*More precisely, Rick pretty much tricked me into doing a day of consulting for $15K, then revealed that’s what he’d done, expressing the thought that he’d very much gotten his money’s worth. But I digress …
ScaleDB has no customers to date, but hopes to be in beta by the end of this year. Angels and a small VC firm have provided bridge loans; otherwise, ScaleDB has no outside investment. ScaleDB’s business model thoughts include: Read more
| Categories: Data models and architecture, Mid-range, MySQL, OLTP, Open source, ScaleDB, Theory and architecture | 5 Comments |
Kalido — CASE for complex data warehouses
Kalido briefed me last week, under pre-TDWI embargo. To a first approximation, their story is confusingly buzzword-laden, as is evident from their product names. The Kalido suite is called the Kalido Information Engine, and it comprises:
- Kalido Business Information Modeler (the newest part)
- Kalido Dynamic Information Warehouse
- Kalido Universal Information Director
- Kalido Master Data Management
But those mouthfuls aside, Kalido has some pretty interesting things to say about data warehouse schema complexity and change.
| Categories: Data integration and middleware, Data models and architecture, Data warehousing, EAI, EII, ETL, ELT, ETLT, Kalido, Theory and architecture | 1 Comment |
Dan Weinreb on ObjectStore
Dan Weinreb was one of the key techies at Object Design, the company that made the object-oriented database management system ObjectStore. (Object Design later merger into Excelon, which was eventually sold to Progress, which has deemphasized but still supports ObjectStore.) Recently he wrote a pair of long and fascinating articles* about Object Design, ObjectStore, and OODBMS, the first of which makes the case that “object-oriented database management systems succeeded.”
Read more
CouchDB — lazy database design taken to excess?
I’ve run into a research/alpha/whatever project called CouchDB a couple of times now. It’s yet another “Who needs relational databases? Who needs schemas?” kind of idea. Rather, CouchDB is for taking random documents and banging them into databases, then calculating views on the fly as needed. It’s REST-friendly. Lucene and a web server are built in.
Damien Katz seems to be the driving force behind CouchDB, and his discussion of document-oriented development seems to be a good starting point. Read more
| Categories: CouchDB, Data models and architecture, Database diversity, Structured documents, Theory and architecture | 4 Comments |
A passionate defense of MapReduce
Mark Chu-Carroll has weighed in with a passionate defense of MapReduce. I only see one thing he got wrong, which was to overlook the great shared-nothing parallelism of today’s data warehouse appliances and specialty data warehouse DBMS. But that doesn’t detract from his overall point, which is that MapReduce is designed to help with parallel computing in general, not database querying in particular.
He also has the best version I know of an old observation, namely:
… [relational database] people have found the most beautiful, wonderful, perfect hammer in the whole world. It’s perfectly balanced – not too heavy, not too light, and swings just right to pound in a nail just right every time. The grip is custom-made, fitted to the shape of the owners hand, so that they can use it all day without getting any blisters. It’s also beautifully decorated – encrusted with gemstones and gold filigree – but only in places that won’t detract from how well it works as a hammer. It really is the greatest hammer ever. Relational database guys love their hammer. It’s just such a wonderful tool! And when they make something with it, it really comes out great. In fact, they like it so much that they think it’s the only tool they need. If you give them a screw, they’ll just pound it in like it’s a nail. And when you point out to them that dammit, it’s a screw, not a nail, they’ll say “I know that. But you can’t expect me to use a crappy little screwdriver when I have a magnificent hammer like this!”
| Categories: Data models and architecture, Database diversity, MapReduce, Parallelization | Leave a Comment |
A sane article from a strict relational advocate
Anybody who cites — with approval — both Fabian Pascal and Joe Celko can’t be all bad. “Why Programmers Don’t Like Relational Databases” is a bit polemic, but on the whole it’s a good reminder of why relational-bashing often is overdone.
Personally, I think the applications for which traditional schema-heavy relational/SQL programming make sense are less interesting that those for which it doesn’t — but the world is indeed chock full of less interesting tasks.