You can download the poster from Itzik Ben-Gan’s T-SQL Querying page over here.
Earlier this year, I had written article on SQL SERVER – Logical Query Processing Phases – Order of Statement Execution and I had asked one question to readers. I got very good response for this question. Today, I am going to discuss about one of the errata I have made there. I had displayed the Logical Query Processing order, where I had incorrectly listed the last two operations. I have listed the operations as ORDER BY first and TOP afterwards. The fact is that TOP is always executed first and ORDER BY after that.
SQL Server never stops to amaze me. As regular readers of this blog already know that besides conducting corporate training, I work on large-scale projects on query optimizations and server tuning projects. In one of the recent projects, I have noticed that a Junior Database Developer used the query hint Force Order; when I asked for details, I found out that the basic concept was not properly understood by him.