Is Semantic Web Technology Scalable?
"Scalable" is a politician of a word. It has attractiveness to obtain solid backing from diverse factions- it has something to offer both the engineericans and the marketerists. At the same time it has the dexterity to mean different things to different people, so that the sales team can always argue that the competition's product lacks "scalability". The word even supports multiple mental images- you can think of soldiers scaling a wall or climbers scaling a mountain; a more correct image is that of scaling a picture to making it bigger. Even technology cynics can get behind the word "scalable": if a technology is scalable, they would argue, that means it hasn't been scaled.
The fact is that scalability is a complex attribute, more easily done in the abstract than in the concrete. I've long been a cynic about scalability. A significant fraction of engineers who worry about scalability end up with solutions that are too expensive or too late to meet the customer problems at hand, or else they build systems that scale poorly along an axis of unexpected growth. Another fraction of engineers who worry too little about scalability get lucky and avoid problems by the grace of Moore's Law and its analogs in memory storage density, processor power and bandwidth. On the other hand, ignorance of scalability issues in the early phases of a design can have catastrophic effects if a system or service stops working once it grows beyond a certain size.