Listing MySQL JOINS with no index

Question

Is there a way to generate a list of JOINS being performed without indexes in MySQL?

Answer 1

If you have available a list of SELECT queries your application performs, just put log-queries-not-using-indexes in your my.cnf, restart MySQL and execute all the SELECTs. Then read the log file.

Alternatively you can run EXPLAIN SELECT your_query_using_JOIN and read the output.