Analytic functions in Oracle SQL are very useful and are utilized by many people, but sometimes without completely understanding how they work or what data they operate on. This article does not focus on a specific function, but on analytic… Continue Reading
One of the most basic tasks you need to perform when tuning SQL statements is determining the causes of the performance problem, and to do that, you will most likely need to analyze the execution plan of the problematic statement.… Continue Reading
I decided to write about Top-N queries today because even though there are lots of articles and documentation about the correct way to do it in Oracle out there, I have seen this question asked on different forums, and to… Continue Reading
CASE expressions are the standard way to implement IF … THEN … ELSE logic in SQL statements. Oracle provides the DECODE function, which does something similar and is widely used by Oracle developers, but CASE expressions are actually more flexible… Continue Reading
This time I’m just writing to tell you a story about the WITH clause, because it is really powerful and vastly underutilized. You can read the basics about the WITH clause in my previous article about subqueries. So, this is… Continue Reading