MariaDB High Performance

The show explain command

The show explain feature is only available in MariaDB 10. It allows you to get an explanation directly from a running process, for example, if you use the loop.sql script once again. At the time of insertion, execute a show processlist command:

MariaDB [chapter2]> SHOW PROCESSLIST\G;
[...]
*************************** 2. row ***************************
      Id: 81
    User: root
    Host: localhost
      db: chapter2
 Command: Query
    Time: 0
   State: query end
    Info: INSERT INTO `s_explain`(`id`, `ts`) VALUES (FLOOR(RAND() * @MAX_INSERT), NOW())
Progress: 0.000
2 rows in set (0.00 sec)

We can see here the 81 ID, which is the INSERT command in the loop.sql script. We're going to analyze it with the show explain command:

MariaDB [chapter2]> ...