Modifying the column data type can be done as follows:
shell> pt-online-schema-change D=employees,t=employees,h=localhost -u root --ask-pass --alter="MODIFY COLUMN address VARCHAR(100)" --alter-foreign-keys-method=auto --executeEnter MySQL password: No slaves found. See --recursion-method if host server1 has slaves.Not checking slave lag because no slaves were found and --check-slave-lag was not specified.Operation, tries, wait: analyze_table, 10, 1 copy_rows, 10, 0.25 create_triggers, 10, 1 drop_triggers, 10, 1 swap_tables, 10, 1 update_foreign_keys, 10, 1Child tables: `employees`.`dept_emp` (approx. 331143 rows) `employees`.`titles` (approx. 442605 rows) `employees`.`salaries` (approx. 2838426 rows) `employees`.`dept_manager` ...
