thread_id BIGINT UNSIGNED NOT NULL, type INT UNSIGNED NOT NULL, space_id INT UNSIGNED, page_no INT UNSIGNED, index_id BIGINT UNSIGNED, table_id BIGINT UNSIGNED, old_file_path VARCHAR(512) COLLATE UTF8_BIN, new_file_path VARCHAR(512) COLLATE UTF8_BIN, KEY(thread_id) ); 

• id : A unique identifier for a DDL log record. 

• thread_id : Each DDL log record is assigned a thread_id , which is used to replay and remove DDL logs that belong to a particular DDL operation. DDL operations that involve multiple data file operations generate multiple DDL log records. 

• type : The DDL operation type. Types include FREE  (drop an index tree), DELETE  (delete a file), RENAME (rename a file), or DROP  (drop metadata from the mysql.innodb_dynamic_metadata  data dictionary table). 

• space_id : The tablespace ID. 

• page_no : A page that contains allocation information; an index tree root page, for example. 

• index_id : The index ID. 

• table_id : The table ID. 

• old_file_path : The old tablespace file path. Used by DDL operations that create or drop tablespace files; also used by DDL operations that rename a tablespace. 

• new_file_path : The new tablespace file path. Used by DDL operations that rename tablespace files. 

This example demonstrates enabling innodb_print_ddl_logs  to view DDL logs written to strderr  for a CREATE TABLE  operation. 

mysql> SET GLOBAL innodb_print_ddl_logs=1; mysql> CREATE TABLE t1 (c1 INT) ENGINE = InnoDB; 

[Note] [000000] InnoDB: DDL log insert : [DDL record: DELETE SPACE, id=18, thread_id=7, space_id=5, old_file_path=./test/t1.ibd] [Note] [000000] InnoDB: DDL log delete : by id 18 [Note] [000000] InnoDB: DDL log insert : [DDL record: REMOVE CACHE, id=19, thread_id=7, table_id=1058, new_file_path=test/t1] [Note] [000000] InnoDB: DDL log delete : by id 19 [Note] [000000] InnoDB: DDL log insert : [DDL record: FREE, id=20, thread_id=7, space_id=5, index_id=132, page_no=4] [Note] [000000] InnoDB: DDL log delete : by id 20 [Note] [000000] InnoDB: DDL log post ddl : begin for thread id : 7 [Note] [000000] InnoDB: DDL log post ddl : end for thread id : 7 

## 13.1.2 ALTER DATABASE Statement 

ALTER {DATABASE | SCHEMA} [ db_name ] alter_option  ... alter_option : { [DEFAULT] CHARACTER SET [=] charset_name | [DEFAULT] COLLATE [=] collation_name | [DEFAULT] ENCRYPTION [=] {’Y’ | ’N’} | READ ONLY [=] {DEFAULT | 0 | 1} } 

