Optimizing MySQL Stored Routines

MySQL stored routines (functions, procedures, triggers and events) can be useful. But many casually written stored routines are unnecessarily slow. The main reason is that MySQL does not apply even simple code optimizations to stored routine code. Many developers are not aware of this, and as a result, write stored routine code that can quite easily be tuned, increasing performance by 50%-100% by only applying very straightforward code optimizations.

During this session, I will present a few real-world stored routines. Most of them were at some point sent to me by users running these procedures in production environments. I will demonstrate a few step-wise improvements, and show graphs to illustrate the effect on performance. The goal of the session is to make developers aware of potential issues in their own stored procedures, and have them takeaway a few practical solutions to avoid these issues in the first place.

Specific topics include:

• impact of simple assignments
• handling and raising errors
• cursors and how to avoid them
• the impact of dynamic sql
• recursion and iteration
• choosing the right control structures