optimizer Archives - Oracle SQL Tips, Tricks and Hacks

Count(*) Vs Count(1) Again?

Posted on January 31, 2017 by Carlos

I decided to write this article because the question about COUNT(*) Vs COUNT(1) keeps being asked, and I usually find myself explaining my answer again and again and/or looking for links to someone else’s articles that can help support my… Continue Reading →

Understanding a Query’s Execution Plan

Posted on January 30, 2016 by Carlos

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 →