ACM Technews, Volume 6, Issue 702: Monday, October 4, 2004, summarizes an interview with Fabian Pascal on misconceptions about databases and data management that are common in database systems practice and development.
I found the full interview informative. One of Fabian's points is that what is commonly known about data models, databases, and database management systems, is not grounded in basic understandings of data, logic, and modeling. It is learned through experience with applications and products, many of which have taken liberties with realizing relational data model ideas and standards such as SQL.
Fabian's critiques of current practice, particularly with XML, is also instructive. I know it seems pedantic, but we need to be clear about what our languages, standards, and practices can and cannot provide.