I was wondering why one of my sites has a performance problem. After a deep look at the structure of my database tables i have discovered that there is a mess between the different storage engines. For this particular site i decide to use only one storage engine for all my tables. The decision was to use MyISAM for all tables.
To identify the tables that use a specific engine (in our example InnoDB) i have used this piece of sql code:
SELECT concat('alter table ',table_schema,'.',table_name,' engine=MyISAM;')
FROM information_schema.tables
WHERE engine = 'InnoDB'
The result is a list of predefined SQL commands for every table. Just use this commands from the results set and make your alter table.
Enjoy.