How to understand which sql queries load the processor?

Question

SQL

Good evening.
The situation is banal - the site uses 90% of the CPU under light load, suspicion of the database, because it is written crookedly. How to detect the place where the most expensive / frequent queries to the database are located? File, statistics table, or specific query. Are there tools that will allow you to do this?
Thanks in advance.

Answer 1

First, look at htop to see if it's really a database.
In the case of mysql, you can log slow queries via my.cnf https://dev.mysql.com/doc/refman/5.7/en/slow-query...
In the case of postgresql - https://www.heatware. net/databases/how-to-find-log...

Answer 2

Just a suspicion?
Need to be more precise.
If on Linux, then look in the top what loads the percent, if Windows is a task manager.
Naturally, there are tools for profiling the database, you just need to know which database server you are using - each has its own tool.