I copied the following here for my convenience. Original source: https://www.taogenjia.com/2020/06/08/mysql-explain/ The type Column The MySQL manual says this column shows the “join type”, but it’s more accurate to say the access type. In other words, how MySQL has decided
MySQL Stored Procedures
Here is a tip you can use when writing a stored procedure, and using prepared statements. Since you have to pass the statements in through EXECUTE stmt USING … it can get confusing if there are a large number of
SQL EXPLAIN: The “Extra” column
This column contains additional information about how MySql resolved the query. There is a line in the manual which states: If you want to make your queries as fast as possible, look out for Extra values of Using filesort and Using temporary. Let’s examine why