Tag: optimization


Updated: ClusterControl Tips & Tricks: MySQL Query Performance Tuning

Bad query performance is the most common problem DBA’s have to deal with. There are numerous ways to collect, process and analyze the data related to query performance – we’ve covered one of the most popular tools, pt-query-digest, in some of our previous blog posts: Become a MySQL DBA blog series When you use ClusterControl …

Performance, Troubleshooting

What to Do When the MySQL Optimizer Overestimates the Condition Filtering Effect

In my previous blog post, I showed an example of how the MySQL Optimizer found a better join order by taking into account the filtering effects of conditions. I also explained that for non-indexed columns the filtering estimate is just a guess, and that there is a risk for non-optimal query plans if the guess …