About the Talk
April 15, 2010 9:00 AM
Billund, DenmarkBillund, Denmark
Part 1: The Mathematics. The relational model of data is based on two mathematical disciplines: set theory and logic. We will introduce some of the principles help us deal with queries (and constraints for that matter), in a formal manner. The very important principle of a 'rewrite rule' will be the main topic in this part. Part 2: Write correct SQL and know it. In Part 2 we show that some of the mathematical concepts are missing in SQL. Luckily we can apply rewrite rules to find equivalent expressions in SQL. We will show examples of queries (and constraints) that have straightforward mathematical specificaitons, but cannot be translated into SQL, without first rewriting them. So in summary, by attending this presentation, you will discover the mathematical concepts that SQL lacks, and that sometimes block you in writing a seemingly simple query. And you'll see how by first specifying such a query mathematically, you enable yourself to quickly deduce how to write the query in SQL by applying (mathematical) rewrite rules.