MySQL Show profile

First, what is Show profile?　　　　Is MySQL provides a measure of the resource consumption that can be used to analyze the execution of statements in the current session, which can be used for SQL tuning. By default, the parameter is turned off and the last 15 run results are saved.

second, the analysis steps 1. Open function, default is off, need to open before use.

3 Select  from EMP Group by id%5;

4. View results, show profiles

5  for query Previous step previous questions SQL number number;

6 , daily development need to pay attention to the conclusion converting HEAP to MyISAM query result is too large, memory is not enough to move to disk. Creating tmp table creates temporary tables coping to TMP on disk copies the in-memory temporary tables to disk, dangerous!! 

MySQL Show profile