query extremely slow after migration to mysql 5.7

Question

I have a MySQL database with InnoDB tables summing up over 10 ten GB of data that I want to migrate from MySQL 5.5 to MySQL 5.7. And I have a query that looks a bit like:

Answer 1

I too faced slow query execution issue after migrating to mysql 5.7 and in my case, even setting session optimizer_switch to 'derived_merge=off'; didn't help.

Then, I followed this link: https://www.saotn.org/mysql-innodb-performance-improvement/ and the query's speed became normal.

To be specific my change was just setting these four parameters in my.ini as described in the link:

innodb_buffer_pool_size

innodb_buffer_pool_instances

innodb_write_io_threads

innodb_read_io_threads