Random RDBMS and SQL Myths debunked

by Roland Bouman

A few times now, I've been wanting to write this down. I know: a lot of people will go *shrug*. Others may find me pedantic. Some of will say I'm being a smart-ass. Whatever...but I just got to write down a few of these common misconceptions that keep floating around.

None of these misconceptions are really harmful - in most cases, they do not lead to misunderstanding or miscommunication. However, when you are writing about these subjects, you'll often find that a sloppy definition you used in some place will bite you in the tail, and make it harder to explain something later on. So, that is why I from time to time get kind of obsessed with finding just the right words.

I'm not pretending I have the right words though. But there are a few informal ways of saying things that at a glance look right but are in fact wrong. Here's a random list of some of them:


2007-11-09 02:28:40
AFAIK InnoDB implements primary key just by sorting rows, there's no separate index involved.
2007-11-09 06:50:17
Here's one: A key is the same as an index.
2007-11-09 14:08:08
I hope you are not promoting the myth that Oracle, MySQL and other SQL DBMSs are actually RDBMSs. :)
2008-01-29 05:53:43
Pedantic? - yes, but still a thought provoking read - Without pedants there'd be no IT.