In my first post in this three part series I talked about the need for
distributed transactional databases that scale-out horizontally across
commodity machines, as compared to traditional transactional databases that
employ a "scale-up" design. Simply adding more machines is a quicker,
cheaper and more flexible way of increasing database capacity than forklift
upgrades to giant steam-belching servers. It also brings the promise of
continuous availability and of geo-distributed operation.
The second post in this series provided an overview of the three historical
approaches to designing distributed transactional database systems, namely:
1. Shared Disk Designs (e.g., ORACLE RAC); 2. Shared Nothing Designs (e.g.
the Facebook MySQL implementation); and 3) Synchronous Commit Designs (e.g.
GOOGLE F1). All of them have some advantages over traditional client-server
Whether you've bought into it yet or not, the Semantic Web (aka Web 3.0) is
coming - and mega-companies are leading the way. Not just the Googles,
Facebooks and Apples of the world, but also massive organizations with
business models as diverse as Wal-Mart, The New York Times, Dow Jones and
Ford. All of them, and many more, are heavily invested in semantic web
One reason: When the transition to the Semantic Web is complete, all data
everywhere will be linked in the cloud as connected points on a massive
global graph. Unlike data in silos, the linked data in graphs ... (more)
As I was traveling across Asia and hanging out in waiting rooms, customs
lines, etc., my mind turns to the future, since the present is so dull. In
our business you always have to keep wondering "What is the next big thing?".
The more I think about it, "Semantics" always seems to bubble up to the top.
To be clear, Semantics is the study of meaning. But its much more than that.
Everything old is new again
Note that I did not say Semantics is the next New thing. In fact, The pursuit
of "Semantic Technology" is by no means a new pursuit. The earliest research
on semantics and compute... (more)
The recent issuance of an RFP for "Unreliable Multicast" in CORBA got me
thinking about the many network semantics available in a combined CORBA/Java
environment. There are at least five already, not counting Unreliable
Multicast: Java RMI invocations; CORBA synchronous invocations; CORBA
asynchronous and messaging-mode invocations; one-way notifications using the
CORBA event and notification services; and the Java Messaging Service (JMS).
In this column I'll review the basic characteristics of these services side
by side. I'm not planning to rate them as "better" or "worse" on a... (more)
Although XML defines each data element in a given transaction (the
semantics), there's no mechanism to also communicate the business context.
This represents the difference between reading XML and understanding the
business impact of the transaction. The use of namespaces, numeric values,
and time stamps all create some context when looking across transactions or
business entities. In this article we'll discuss the difference between
semantics and context and the challenges this difference creates relative to
performance and scalability.
One of the core tenets of XML is its exte... (more)
Much of the literature heralding the benefits of XML has focused on its
application as a medium for application interoperability. With (a) the
Internet as a platform, (b) Web services as the functional building block
components of an orchestrated application, and (c) XML as a common data
format, applications will be able to communicate and collaborate seamlessly
and transparently, without human intervention. All that's needed to make a
reality is (d) for everyone to agree on and use XML tags the same way so that
when an application sees a tag such as it will know what... (more)