SQL Performances Basics

by David H
This article talks about how to write efficient SQL statement that can help to enhance the performance of application. SQL is one of the languages that we can write code for database application. Depending on how good we write the SQL coding, it will effect to the performance of the application. The author Craig Mullins stated “There are 75% of poor relational performance is caused by bad SQL and application code.” This shows that writing an efficient SQL statement is not easy especially for the beginning programmer. Graig Mullins mentioned that there are several step and rules that we need to follow in order to write an efficient SQL statement.  The first step is transform file processing to relational.  Next step is use SELECT SQL statement to retrieve each column. Graig Mullin recommends that don’t use SELECT * all of the time because it may cause application program fail. Third step that he believes many of beginner programmer make mistake is WHERE clause. He recommends that use WHERE clause to filter data in the SQL instead bring it all in to program filter. However, author Craig Mullin make a focal point that it is crucial for DBA to keep database static update. The reason why DBA need to have static update is because it makes easy to optimizing data store in DBMS. In addition, create indexes in queries is also important.

This article relates to class because it explains the basic concept of how we write efficient SQL statement beside what we have been discussed in the class.  From my opinion, writing SQL statement is simple as long as we follow the rule but writing an efficient SQL statement is not easy. I think these steps above are very important that we need to follow and take into consideration in order to improve database application performance.


Mullins, C. S. (2010). SQL Performance Basics. Database Trends And Applications, 24(4), 29.

4 thoughts on “SQL Performances Basics”

  1. great article! it was very informative. I remember when I was doing my project, I actually had a hard to writing SQL statement. this article is very informative thank you for sharing. 🙂

  2. I really enjoyed reading your article. These statements are essential to learn and use effectively, in order to write statements into SQL Server. Its amazing how poor code can negatively effect the efficiency by 75%. This relates to us writing code in our second project.

  3. Writing SQL statements are definitely not easy. I know when doing project 2 I made a few mistakes when writing my statements. However, with every new subject comes the need to practice, practice, practice! I think that once students keep practicing, they will become professionals at writing statements. Thanks for the article David! 🙂

  4. This article was pretty helpful because I don't believe we were able to go over some of this stuff in class. Hopefully we can apply these rules into our own projects or career in the near future.

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