Determine whether InnoDB plugin is installed in MySQL

Question

How do we check Innodb plugin is installed or not in MySQL? Is there any variable to check Innodb Plugin is installed or not?

Answer 1

If you need to determine whether or not InnoDB is enabled by querying the database, you should use the INFORMATION_SCHEMA tables.

SELECT SUPPORT FROM INFORMATION_SCHEMA.ENGINES WHERE ENGINE = 'InnoDB';

Which, if InnoDB is enabled and is the default database, gives a result of

+---------+
| SUPPORT |
+---------+
| DEFAULT |
+---------+

If InnoDB is available, but not the default engine, the result will be YES. If it's not available, the result will obviously be NO.

Please see http://dev.mysql.com/doc/refman/5.5/en/engines-table.html and http://dev.mysql.com/doc/refman/5.5/en/information-schema.html for reference.

When InnoDB is available, the INFORMATION_SCHEMA tables you mentioned in a comment are also available.

SHOW TABLES FROM INFORMATION_SCHEMA LIKE 'INNODB%';

+----------------------------------------+
| Tables_in_INFORMATION_SCHEMA (INNODB%) |
+----------------------------------------+
| INNODB_CMP_RESET                       |
| INNODB_TRX                             |
| INNODB_CMPMEM_RESET                    |
| INNODB_LOCK_WAITS                      |
| INNODB_CMPMEM                          |
| INNODB_CMP                             |
| INNODB_LOCKS                           |
+----------------------------------------+