A user-defined function that returns a table of numbers between a and b (using the most efficient way I can think of).
e.g. select * from table_of_numbers(1, 4) gives a table with rows 1, 2, 3 and 4.
For most DBAs, normalization is an understood concept, a bread and butter bit of knowledge. However, it is not at all unusual to review a database design by a development group for an OLTP (OnLine Transaction Processing) environment and find that the schema chosen is anything but properly normalized. This article by Brian Kelley will give you the core knowledge to data model.