CREATE TABLE Statement COMMENT="NDB_TABLE=READ_BACKUP=0,PARTITION_BALANCE=FOR_RP_BY_NODE" ; Spaces are not permitted within the quoted string. The string is case-insensitive. The comment is displayed as part of the ouput of  SHOW CREATE TABLE . The text of the comment is also available as the TABLE_COMMENT column of the MySQL Information Schema  TABLES  table. This comment syntax is also supported with  ALTER TABLE  statements for  NDB  tables. Keep in mind that a table comment used with  ALTER TABLE  replaces any existing comment which the table might have had perviously. Setting the  MERGE_THRESHOLD  option in table comments is not supported for  NDB  tables (it is ignored). For complete syntax information and examples, see Section 13.1.20.11, “Setting NDB_TABLE Options” . The compression algorithm used for page level compression for  InnoDB  tables. Supported values include  Zlib ,  LZ4 , and  None . The  COMPRESSION  attribute was introduced with the transparent page compression feature. Page compression is only supported with  InnoDB  tables that reside in file-per- table tablespaces, and is only available on Linux and Windows platforms that support sparse files and hole punching. For more information, see Section 15.9.2, “InnoDB Page Compression” . The connection string for a  FEDERATED  table. Older versions of MySQL used a  COMMENT  option for the connection string. For  InnoDB , the  DATA DIRECTORY=’ directory ’  clause permits creating tables outside of the data directory. The  innodb_file_per_table  variable must be enabled to use the  DATA DIRECTORY clause. The full directory path must be specified. As of MySQL 8.0.21, the directory specified must be known to  InnoDB . For more information, see Section 15.6.1.2, “Creating Tables Externally” . When creating  MyISAM  tables, you can use the  DATA DIRECTORY=’ directory ’  clause, the  INDEX DIRECTORY=’ directory ’  clause, or both. They specify where to put a  MyISAM  table’s data file and index file, respectively. Unlike  InnoDB  tables, MySQL does not create subdirectories that correspond to the database name when creating a  MyISAM  table with a  DATA DIRECTORY  or  INDEX DIRECTORY option. Files are created in the directory that is specified. You must have the  FILE  privilege to use the  DATA DIRECTORY  or  INDEX DIRECTORY  table option. Table-level  DATA DIRECTORY  and  INDEX DIRECTORY  options are ignored for partitioned tables. (Bug #32091) These options work only when you are not using the  --skip-symbolic-links  option. Your operating system must also have a working, thread-safe  realpath()  call. See Section 8.12.2.2, “Using Symbolic Links for MyISAM Tables on Unix” , for more complete information. If a  MyISAM  table is created with no  DATA DIRECTORY  option, the  .MYD  file is created in the database directory. By default, if  MyISAM  finds an existing  .MYD  file in this case, it overwrites it. The same applies 2555 Important Note • COMPRESSION • CONNECTION • DATA DIRECTORY ,  INDEX DIRECTORY