MySQL Day – Sessions review #3

On February 3rd, just before Fosdem and the MySQL & Friends Devroom, MySQL’s Community Team is organizing the pre-Fosdem MySQL Day.

Today’s highlighted sessions are the one of Øystein Grøvlen:

  • MySQL 8.0: Common Table Expressions (CTEs)
  • Using Optimizer Hints to Improve MySQL Query Performance

Øystein is Senior Principal Software Engineer in the MySQL group at Oracle, where he works on the MySQL Query Optimizer.  

Dr. Grøvlen has a PhD in Computer Science from the Norwegian University of Science and Technology.  Before joining the MySQL team, he was a contributor on the Apache Derby project and Sun’s Architectural Lead on Java DB.  Prior to that, he worked for 10 years on development of Clustra, a highly available DBMS. Øystein lives in Trondheim, Norway.

Øystein is a regular speakear at events like Oracle Open World, Percona Live, Fosdem, …

So, let’s check the content of the two sessions he will deliver during pre-Fosdem MySQL Day.

The first session is at 11.00AM and is about Common Table Expressions (sometimes referred to as WITH queries).

This is a new feature that will be available in MySQL 8.0. In their simplest form, CTEs are a way of creating a view/temporary table for usage in a single query. This can help improve the readability of SQL code. However, they have many more use cases. In particular, when using the RECURSIVE form of CTEs, it is possible to perform advanced tasks with few lines of code. This session covers CTEs as supported in MySQL 8.0, and will present several examples on how you can benefit from using CTEs.

Øystein’s second session is a 3.00PM and is about MySQL Optimizer.

Some times you will experience that the MySQL Optimizer picks a non-optimal execution plan for your
query. For example, this may happen when the optimizer assumes a uniform distribution of column values while your actual data is skewed. Or when the optimizer’s cost model is based on assumptions about performance of hardware components that are inaccurate for your system. Optimizer hints may in such cases be used to influence the optimizer to choose a more optimal plan. This session will cover the different types of hints available in MySQL, and through several practical examples, it will be shown how using hints may improve query performance. The session will also cover the new optimizer hints that have been introduced in MySQL 5.7 and 8.0.

Don’t forget to register for this main MySQL 8.0 event

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As MySQL Community Manager, I am an employee of Oracle and the views expressed on this blog are my own and do not necessarily reflect the views of Oracle.

You can find articles I wrote on Oracle’s blog.