Transact SQL Performance Tips

SQL Server optimizer doesn't use and index seek for execution of your query although the quer is high selective? What is better, when and why: LIKE vs: SUBSTRING, IN vs. EXISTS, SUBQUERY vs. JOIN. Why you should not use the UPPER or LOWER functions? How to avoid non-SARG-able WHERE clauses? Which query takes about 3 minutes in SQL Server 2008 and only one second in SQL Server 2012?

In this session we will answer these questions and show how bad designed queries lead to poor execution plans. We will offer recommendations and tips how to avoid performance problems caused by poor query design (functions in WHERE clause, data type conversions…) and explain how local variables and parameters affect the generation of execution plan.
Presented by Milos Radivojevic at SQLBits XI
  • Downloads
    Slide deck available Slide Deck 994 KB
    Samples available Demo Code 15 KB
    Video available MP4 Video Med 184 MB
    Video available MP4 Video HD 508 MB
  • SpeakerBIO

    Milos Radivojevic is a database developer, consultant, speaker, and trainer located in Vienna, Austria. He has been working with SQL Server over 15 years. He is Microsoft SQL Server MVP and MCT and specializes in SQL Server for application developers and performance and query tuning. Currently he works as principal database consultant in (the largest regulated online gaming company in the world) where he works with some of the largest SQL Server databases. He is co-leader of the SQL Server PASS Austria. He is a speaker in international conferences (SQLBits, SQL Saturday, Sinergija, SQL Conference) and speaks regularly at SQL Server PASS Austria meetings. His Twitter handle is @MilosSQL.
  • Video