JOINS Current join_buffer_size = 132.00 K You have had 627 queries where a join could not use an index properly You have had 4 joins without keys that check for key usage after each row You should enable "log-queries-not-using-indexes" Then look for non indexed joins in the slow query log. If you are unable to optimize your queries you may want to increase your join_buffer_size to accommodate larger joins in one pass. Note! This script will still suggest raising the join_buffer_size when ANY joins not using indexes are found. This is an outcome from a MySQL optimizing script. I don't get the point in red. What exactly is it telling me to do?
You've got a query which requires mysql to scan the whole tables for the information as opposed to using an index (a key). you can add indexes on the columns you need if your script makes that query a lot. each time that query is made, mysql will then check the table for a key again before moving on to the next row (in order to process the next row faster). this will slow down the time it takes to perform the query.