So I came across an odd situation today.

I have a system that creates memory tables using the PHP  $_COOKIE['PHPSESSID'] value.

Once some work is done it then drops the table.

Two sample tables are below for my example .


@@VERSION: 5.6.19-log
CREATE TABLE `f7a7a8d3a7ba75b5eb1712864c9b27eb` (
    ->   `id` int(11) NOT NULL AUTO_INCREMENT,
    ->   PRIMARY KEY (`id`)
    -> ) ENGINE=MEMORY;

CREATE TABLE `8865e52c7e1bea515e7156f240729275` (
    ->   `id` int(11) NOT NULL AUTO_INCREMENT,
    ->   PRIMARY KEY (`id`)
    -> ) ENGINE=MEMORY;


Now some simple processing occurs on the real tables I used then like I said I dropped them.
…

I would like to share this story based on a true event about the temporary files behavior in MySQL.

MONyog reports this error to my already full mailbox several times a day :

1 – Catch the query (if you can) !

I don’t have access to the client logs but I would like to know which query is involved in this error.

Let me explain how I can retrieve informations about this query with MONyog and a very simple shell loop :

•  Enable the query sniffer in MONyog (based on processlist) : Edit server -> Advanced settings -> Sniffer settings

…