After setting up mariadb and tweaking its basic configuration, one may want to check the structures and sql- queries for performance.

It is not really well documented, how mariadb will output what exactly is the cause for bad performance. In phpMyAdmin there is a tab in the Server-Menu named Status where there is an Advisor, which may give hints for what may be wrong. But after that, there is no way to find the Statements, causing the trouble.

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