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Understanding real-time performance statistics in MySQL

One of MySQL's better-kept secrets is the ability to generate statistics on server usage and performance in real-time. If you're charged with the task of optimizing RDBMS performance, you need to know how to extract these secrets to speed up your database.

MySQL has a lot of secrets...and one of its better-kept ones is the ability to generate statistics on server usage and performance in real-time. This capability allows Web developers, SQL administrators, and others charged with the task of optimizing RDBMS performance to obtain a detailed view of how the server is handling requests and to analyze problems and bottlenecks for corrections. If you're concerned about how your server is performing, or if you're just curious about what's happening behind the scenes, this information is bound to come in useful to you in your role as MySQL administrator.

Among the information available to you, the administrator, is:

  • Server uptime
  • Average time taken per query
  • Number of running queries and the number of open tables
  • Number of times a particular command was executed
  • Query performance, including slow queries and joins
  • Information on open connections and what each client is doing

Each of the pages linked below gives you more detail on how to obtain and understand the performance statistics that MySQL keeps.

How to use the SHOW STATUS command in MySQL

This is the place to start—it gives you a wealth of statistics on how the MySQL database is performing. Learn the basics on how to use the SHOW STATUS command.

Understanding the performance statistics from SHOW STATUS

The SHOW STATUS command spits out a somewhat bewildering array of statistics. Here's a quick guide to some of the more interesting MySQL performance statistics.

How to examine and kill MySQL client processes

Another very useful command when it comes to keeping track of client-server transactions is the SHOW PROCESSLIST command. Learn how to use this command to obtain process information and how to kill any errant MySQL processes.

Specialized status commands in MySQL

A number of other useful commands also exist to obtain other, more specialized types of status information. Here's a handy little crib sheet to some of the specialized status commands in MySQL.

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