One pt-osc is used, and the pt-osc is used.

One pt-osc is used, and the pt-osc is used.

1. Backup before use

Mysqldump-uroot-p fission_statistics room_break_history> room_break_history_201704.dump

2.pt-osc run DDL

Pt-online-schema-change -- user = 'root' -- host = 'localhost' -- ask-pass -- alter "CHANGE break_type INT (11) not null, CHANGE app_id INT (11) not null, CHANGE room_id INT (11) not null, CHANGE from_user_id INT (11) not null, CHANGE to_user_id INT (11) not null, CHANGE content_type INT (11) not null, CHANGE source_message VARCHAR (1536) CHARSET utf8mb4 COLLATE does not null, CHANGE send_message VARCHAR (1536) CHARSET utf8mb4 COLLATE does NOT NULL, CHANGE request_type INT (4) not null, CHANGE handle_type INT (11) not null, CHANGE handle_uid INT (11) not null, CHANGE create_time datetime not null, drop index idx_from_user_id, add index idx_handle_time (handle_type, create_time) "D = fission_statistics, t = room_break_history -- execute