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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” . 

## 15.23 InnoDB Restrictions and Limitations 

This section describes restrictions and limitations of the InnoDB  storage engine. 

•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. 

mysql> CREATE TABLE t1 (c1 INT, db_row_id INT) ENGINE=INNODB; ERROR 1166 (42000): Incorrect column name ’db_row_id’ 

• 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. 

For information about how InnoDB  processes SELECT COUNT(*)  statements, refer to the COUNT() description in Section 12.20.1, “Aggregate Function Descriptions” . 

• 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. 

