MySQL 5.7.5でmysqlスキーマの中身がちょっとだけInnoDB化された

MySQL 5.7ではmysqlスキーマのテーブルがいくつかMyISAM => InnoDB化されている。

5.6ではInnoDB統計情報永続化のヤーツと{master|relay-log}_info_repositoryのヤーツだけだったのが、

mysql56> SELECT @@version;
+------------+
| @@version  |
+------------+
| 5.6.20-log |
+------------+
1 row in set (0.00 sec)

mysql56> SELECT table_name, engine FROM information_schema.tables WHERE table_schema= 'mysql';
+---------------------------+--------+
| table_name                | engine |
+---------------------------+--------+
| columns_priv              | MyISAM |
| db                        | MyISAM |
| event                     | MyISAM |
| func                      | MyISAM |
| general_log               | CSV    |
| help_category             | MyISAM |
| help_keyword              | MyISAM |
| help_relation             | MyISAM |
| help_topic                | MyISAM |
| innodb_index_stats        | InnoDB |
| innodb_table_stats        | InnoDB |
| ndb_binlog_index          | MyISAM |
| plugin                    | MyISAM |
| proc                      | MyISAM |
| procs_priv                | MyISAM |
| proxies_priv              | MyISAM |
| servers                   | MyISAM |
| slave_master_info         | InnoDB |
| slave_relay_log_info      | InnoDB |
| slave_worker_info         | InnoDB |
| slow_log                  | CSV    |
| tables_priv               | MyISAM |
| time_zone                 | MyISAM |
| time_zone_leap_second     | MyISAM |
| time_zone_name            | MyISAM |
| time_zone_transition      | MyISAM |
| time_zone_transition_type | MyISAM |
| user                      | MyISAM |
+---------------------------+--------+
28 rows in set (0.00 sec)

5.7.5では

mysql> SELECT @@version;
+---------------+
| @@version     |
+---------------+
| 5.7.5-m15-log |
+---------------+
1 row in set (0.05 sec)

mysql> SELECT table_name, engine FROM information_schema.tables WHERE table_schema= 'mysql';
+---------------------------+--------+
| table_name                | engine |
+---------------------------+--------+
| columns_priv              | MyISAM |
| db                        | MyISAM |
| engine_cost               | InnoDB |
| event                     | MyISAM |
| func                      | MyISAM |
| general_log               | CSV    |
| gtid_executed             | InnoDB |
| help_category             | InnoDB |
| help_keyword              | InnoDB |
| help_relation             | InnoDB |
| help_topic                | InnoDB |
| innodb_index_stats        | InnoDB |
| innodb_table_stats        | InnoDB |
| ndb_binlog_index          | MyISAM |
| plugin                    | MyISAM |
| proc                      | MyISAM |
| procs_priv                | MyISAM |
| proxies_priv              | MyISAM |
| server_cost               | InnoDB |
| servers                   | MyISAM |
| slave_master_info         | InnoDB |
| slave_relay_log_info      | InnoDB |
| slave_worker_info         | InnoDB |
| slow_log                  | CSV    |
| tables_priv               | MyISAM |
| time_zone                 | InnoDB |
| time_zone_leap_second     | InnoDB |
| time_zone_name            | InnoDB |
| time_zone_transition      | InnoDB |
| time_zone_transition_type | InnoDB |
| user                      | MyISAM |
+---------------------------+--------+
31 rows in set (0.00 sec)

:(；ﾞﾟ'ωﾟ'): おいmysql_install_dbとmysql_upgradeしか触らないようなテーブルじゃまいか。

engine_cost, server_cost, gtid_executedが新設テーブルですね。