Tables existence check query is executed in large quantities

When Rails starts, tables existence check query is executed number of models.
In case of mysql,

    SHOW TABLES LIKE 'table1';
    SHOW TABLES LIKE 'table2';
    SHOW TABLES LIKE 'table3';
    ...
    SHOW TABLES LIKE 'table999';

Add process to get the names of all tables by one query.
yes.. but you could have 2 processes, one deletes the table(rake task), the other process(rails s) doesnt receive a `clear_table_cache!` , as they dont share memory.