Most relational databases support the use of a null value to represent an absence of data. Nulls can confuse both data warehouse developers and users because the database treats nulls differently from blanks or zeros, even though they look like blanks or zeros. This design tip explores the three major areas where we find nulls in our source […]

Dimensional modeling is a design discipline that straddles the formal relational model and the engineering realities of text and number data. Compared to entity/relation modeling, it’s less rigorous (allowing the designer more discretion in organizing the tables) but more practical because it accommodates database complexity and improves performance. Contrasted with other modeling disciplines, dimensional modeling […]