MySQL EXPLAIN, explained - Seguridad Mania.com - España y América Latina

Most general performance issues come down to query performance. Once you've identified a query that requires further examination using SHOW PROCESSLIST, Performance Schema, the Slow Query Log, or MySQL Enterprise Monitor's Query Analyzer, you then need to determine exactly *why* it was slow. In order to do that, you need to determine what the MySQL optimizer did when executing it, what it is likely to do when executing it in the future, and why it made those decisions. This is where EXPLAIN (including the new JSON based output), along with the new Optimizer Trace feature, provides you with the needed information to understand what happened, why, and how you can tweak the query, your schema, or the optimizer itself in order to improve the query's performance. As we go along, we'll also demonstrate how the new Visual Explain functionality available in MySQL Workbench 6.1 helps us to visualize these results. In this technical webinar we will cover:•A deep dive into traditional EXPLAIN output •An introduction to the new JSON based EXPLAIN output •The Visual Explain 2.0 functionality in MySQL Workbench 6.1 •An introduction to the new Optimizer Trace functionality Presenters: Øystein Grøvlen, Senior Principal Software Engineer Matt Lord, MySQL Product Manager