Understanding a Query’s Execution Plan

HotSpot feature in SQL Developer

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. In this article, I cover the basics of execution plans, with… Read more »

The WITH clause to the rescue!

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 the story about how it helped a couple of guys… Read more »

Oracle Inner Join Syntax : 4 different ways

I’ve worked with Oracle databases for many years, and during this time I have seen code written by lots of different people. One thing I have noticed is that with few exceptions, people who started working with Oracle many years ago tend to write joins in some way and people… Read more »

Oracle NVL, NVL2 and COALESCE functions

I have seen quite a few questions on internet forums and knowledge exchange sites about Oracle NVL, NVL2 and COALESCE functions for handling nulls, so I decided to write an article about them today. Those functions are actually similar, but knowing what differentiates them from each other can help you… Read more »