…), KEY K(id2)) engine=INNODB; when table has to be traversed in both directions for different queries. This will use fast primary key… too many? A: There is a hard limit on amount of indexes you can have, which is 64 per table in recent MySQL versions. However…. Also check out my old article on the topic which goes into a lot more details. Q: how mysql use index for group by? A: If…

…table which would look as following in terms of data and index size: mysql> show table status like “sbtest” \G *************************** 1. row *************************** Name: sbtest Engine…Check…which builds table with primary key only when creating a table…

…tables and indexes (with their IDs) to the error log. mysql (employees) > CREATE TABLE innodb_table_monitor (id int) ENGINE=InnoDB; TABLE…mysql-data-recovery:generating_a_table_definition With the table definition on table…

…MySQL manual tells us that regardless of whether or not we use “SET FOREIGN_KEY_CHECKS…ENGINE=INNODB; trying to do something like “ALTER TABLE bar DROP j” or “ALTER TABLE…, which is also what we’d expect: table “foo” and table “bar”… suppose that this was actually a long-running ALTER statement. Maybe…