InnoDB Restrictions and Limitations InnoDB Page Size Maximum Tablespace Size 16KB 64TB 32KB 128TB 64KB 256TB The maximum tablespace size is also the maximum size for a table. •The path of a tablespace file, including the file name, cannot exceed the  MAX_PATH  limit on Windows. Prior to Windows 10, the  MAX_PATH  limit is 260 characters. As of Windows 10, version 1607,  MAX_PATH limitations are removed from common Win32 file and directory functions, but you must enable the new behavior. •For limits associated with concurrent read-write transactions, see Section 15.6.6, “Undo Logs” . •You cannot create a table with a column name that matches the name of an internal  InnoDB  column (including  DB_ROW_ID ,  DB_TRX_ID , and  DB_ROLL_PTR . This restriction applies to use of the names in any lettercase. • SHOW TABLE STATUS  does not provide accurate statistics for  InnoDB  tables except for the physical size reserved by the table. The row count is only a rough estimate used in SQL optimization. • InnoDB  does not keep an internal count of rows in a table because concurrent transactions might “see” different numbers of rows at the same time. Consequently,  SELECT COUNT(*)  statements only count rows visible to the current transaction. • ROW_FORMAT=COMPRESSED  is unsupported for page sizes greater than 16KB. •A MySQL instance using a particular  InnoDB  page size ( innodb_page_size ) cannot use data files or log files from an instance that uses a different page size. •For limitations associated with importing tables using the  Transportable Tablespaces  feature, see Table Import Limitations. •For limitations associated with online DDL, see Section 15.12.6, “Online DDL Limitations” . •For limitations associated with general tablespaces, see General Tablespace Limitations. •For limitations associated with data-at-rest encryption, see Encryption Limitations. 3396 For information about how  InnoDB  processes  SELECT COUNT(*)  statements, refer to the  COUNT() description in Section 12.20.1, “Aggregate Function Descriptions” . mysql>  CREATE TABLE t1 (c1 INT, db_row_id INT) ENGINE=INNODB; ERROR 1166 (42000): Incorrect column name ’db_row_id’ This section describes restrictions and limitations of the  InnoDB  storage engine. 15.23 InnoDB Restrictions and Limitations